It's nothing more but grunt work that can be done by literally anyone. You hire additional 3D model artists and animators to do the job. It's in no way "impossible" except if you don't want to put in the effort.

Also, remember this quote from a certain fellow?

"A delayed game is eventually good, but a rushed game is forever bad."

This is just a part of a bigger trend of GF cutting features with no good reason. It's absolutely the worst of them, but here is everything else in list form:

2003:

• The day-night cycle, a big part of the Gen II games, is removed from Ruby/Sapphire and doesn't return until Gen IV on the DS.

2011:

• The release of Pokemon Black & White saw the loss of Pokemon Contests, and other alternatives to battling. After the improvements Gen 4 did to Contests just for them to just, disappear, never to be seen again until ORAS where they just felt tacked on.
• Secret Bases or other kinds of player housing were also cut. Gen 4 made player housing a staple, with the secret bases in the underground, or the custom Safari Zone in HGSS. Secret Bases only returned for ORAS then disappeared after that.

2013:

• Seasons, a major feature that was added in Gen V, had now been cut. Seasons made the world feel more alive and allowed for more Pokemon to spawn, and it felt like a natural evolution of the series, only to have it appear in one generation.
• The difficulty select from Gen V is also cut. The games now once again only has one specific difficulty.
• Pokemon Transfers were also no longer a free feature and were transferred into a $5 a year service, so once the service shuts down those Pokemon will no longer be transferable.

2014:

• The Game Corner was cut, despite being in the original Gen 3. HGSS managed to find a way to keep the Game Corner by making it a fun place for non-gambling minigames with Voltorb Flip. But in ORAS, they decided not to bother. The Game Corner in LGPE was just decoration.
• The Battle Frontier was also cut, what was also a staple of Gen 3 since it was the first gen to have a massive Postgame facility like that with more replayablity. Their excuse to why it didn't come back was because "it was too overwhelming for kids nowadays."

2016:

• The National Dex is removed from the games, the in-game Pokedex no longer tracks all of your Pokemon, just those in the regional dex.
• Triple and Rotation battles were cut. These two new battle formats were major editions in Gen 5 and stayed in Gen 6, and for some were their favorite way to battle. The reasoning for their exclusion is unknown.
• Horde Battles were also cut, replaced with random wild Pokemons joining in. No more than 2 Pokemon will be out at once.
• Chaining was cut with the absence of the PokeRadar.
• Berry growing is cut. Berries now just spawn randomly in mass in trees. Berry growing used to allow you to choose what berries you got and allowed you to grow said berries in mass. Now you just wait for a berry pile and pray the berries you want are in them.
• While Megas were still in, they were pretty much cut and replaced with Z-Moves with no new Megas. Now with Sword and Shield it appears Z-Moves have now suffered the same fate as now Dynamaxing is the gimmick of the generation.

2018:

• All but the first 151 not present in LGE/LGP
• Every one of these standard main series features not present in LGE/LGP; with the promise that a mainline 'hardcore' focused Pokemon would come in 2019.
  • Day/Night Cycle
  • Fishing
  • A lot of moves
  • Friendship evolutions
  • Breeding
  • EVs
  • Abilities
  • Wild Battles
  • Held Items
  • Double Battles
  • GTS
  • Wonder Trade
  • Battle Spot

2019:

• Full Pokemon compatibility removed from the game

Everything they said about LGE/LGP not effecting the main series, and SW/SH being mainline hardcore fan focused games is complete bullshit. Let's Go was nothing more than a test to see how the market would react to a stripped down Pokemon game and it sold 10m+. They now know they can put as little effort as possible, and not even have it be their main focus, but still it will sell bonkers. I can't wait to see what else got cut.

It's nothing more but grunt work that can be done by literally anyone. You hire additional 3D model artists and animators to do the job. It's in no way "impossible" except if you don't want to put in the effort.

Also, remember this quote from a certain fellow?

"A delayed game is eventually good, but a rushed game is forever bad."

Part of it is laziness, but I think most of the problem is a complete unwillingness to expand as a studio. Gamefreak is the only developer of a 10m+ per game selling franchise to have less than 200 developers as far as I know. Even worse, not all of their 143 devs work on a single game, they are most likely currently working on 4-5 different projects; Sword/Shield, Giga Wrecker Alt, Town, Sword and Shield's 3rd version, and possibly Gen 4 remakes or Let's Go Gen 2 remakes are already in early development. There's no denying that Gamefreak is woefully understaffed to be handling a franchise as popular as Pokemon, where even the remakes sell over 10m and the main games push pretty close to 20m. 

Comparison of Gamefreak's size to other studios that develop games that sell over 10m:

-Pokemon- Gamefreak- 143 devs split across multiple teams

-The Last of Us, Uncharted 4- Naughty Dog- 497 devs (most likely currently split into 2 team, the larger team on The Last of Us 2 and the smaller on a different game)

-Horizon Zero Dawn- Guerrilla Games- 250 devs (plans to expand to 400 after moving to a new building so that they can develop 2 games at once)

-Red Dead Redemption 2- Rockstar- Exact developer count unknown, but Rockstar claims that it was a collaborative effort with work on the game being done by teams at all of their studios, and they employ 2000 people across all of their studios, so probably at least 1000 people worked on the game in some capacity.

-Elder Scrolls and Fallout- Bethesda- Bethesda staffed up to around 200 for their last main game, Falllout 4, and are currently staffed up to 400+ devs across 4 studios

-The Witcher and Cyberpunk- CD Projekt Red- Witcher 3 started development with 150 full-time devs, increasing to 250 before the game was finished, and 1500 total people worked on the game in some capacity, between contract developers and localization teams. They have staffed up for their next game, Cyberpunk 2077, with over 400 full-time developers working on the game. 

-Call of Duty- Treyarch, Infinity Ward, and Sledgehammer- Treyarch and Infinity Ward each have over 500 devs now, while Sledgehammer is down to 225 after the studio founders quit and took a bunch of the staff with them last year. 

-God of War 4- Sony Santa Monica- 200+ devs

Part of it is laziness, but I think most of the problem is a complete unwillingness to expand as a studio. Gamefreak is the only developer of a 10m+ per game selling franchise to have less than 200 developers as far as I know. Even worse, not all of their 143 devs work on a single game, they are most likely currently working on 4-5 different projects; Sword/Shield, Giga Wrecker Alt, Town, Sword and Shield's 3rd version, and possibly Gen 4 remakes or Let's Go Gen 2 remakes are already in early development. There's no denying that Gamefreak is woefully understaffed to be handling a franchise as popular as Pokemon, where even the remakes sell over 10m and the main games push pretty close to 20m. 

Comparison of Gamefreak's size to other studios that develop games that sell over 10m:

-Pokemon- Gamefreak- 143 devs split across multiple teams

-The Last of Us, Uncharted 4- Naughty Dog- 497 devs (most likely currently split into 2 team, the larger team on The Last of Us 2 and the smaller on a different game)

-Horizon Zero Dawn- Guerrilla Games- 250 devs (plans to expand to 400 after moving to a new building so that they can develop 2 games at once)

-Red Dead Redemption 2- Rockstar- Exact developer count unknown, but Rockstar claims that it was a collaborative effort with work on the game being done by teams at all of their studios, and they employ 2000 people across all of their studios, so probably at least 1000 people worked on the game in some capacity.

-Elder Scrolls and Fallout- Bethesda- Bethesda staffed up to around 200 for their last main game, Falllout 4, and are currently staffed up to 400+ devs across 4 studios

-The Witcher and Cyberpunk- CD Projekt Red- Witcher 3 started development with 150 full-time devs, increasing to 250 before the game was finished, and 1500 total people worked on the game in some capacity, between contract developers and localization teams. They have staffed up for their next game, Cyberpunk 2077, with over 400 full-time developers working on the game. 

-Call of Duty- Treyarch, Infinity Ward, and Sledgehammer- Treyarch and Infinity Ward each have over 500 devs now, while Sledgehammer is down to 225 after recent disarray at the studio. 

-God of War 4- Sony Santa Monica- 200+ devs

-Borderlands 2- Gearbox- Gearbox currently employs 368 devs as Borderlands 3's release approaches. 

I said that delaying the games would be impossible, not that putting every pokemon in their would be impossible. Also, what does that quote have to do with anything? Not having every Pokemon in the game isn't a deal breaker nor would it make the games bad

Looking at the current fan reaction, not having every Pokemon seems to be a pretty big deal.

Also, how is a delay impossible? Is Nintendo forced by a higher power they can't possibly defend against? They did delay Animal Crossing. What mystical force did they use to accomplish that?