I'm just a casual pokeman fan, but this does make some sense. Balancing/animating it all out for every game does seem like a lot of work. I would rather have them working on the new game itself, then spending lots of time bringing in all old versions.

Ah I see. Well im not a big Pokemon fan (Only played 3 Mainline pokemon games +Lets Go) sooo it probably didnt and wont bother me. But it does suck for majority of the people. 

meh I personally don't care that it doesn't have all 800 pokemon. Still excited for the game

I don't care. I play for the new Pokemon, region, and story.

Not trying to take away from this...but didn't Sun and Moon also technically only have a Regional Pokedex? I might be off base here, obviously it lets you bring any Pokemon into the game, but I remember thinking my Pokedex wasn't updating for some reason when I brought a Charizard into my file, and someone at the time told me that the National Dex was in Pokebank now. If that was true, maybe the idea is that cross-game collection is limited to Bank (or whatever the new version of Bank is), and collecting in the games themselves is now limited to the Regional dexes.

If that's true...still annoying for people that like to bring their teams across games, but I can understand the idea a little more.

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.

Lol i must be one of hte few people who don't transfer their pokemon. I leave them int he game i caught them.

Might be time to get myself into the latest trends and see how all this works lol

By the way, I don't want to ask for something too amazing, or be too greedy...

But still no save files management? I think it was still like this with SM (could be wrong), but are we still at the Game Boy era when you little brother could delete your entire game because he wanted to play his own game?

Yeah, surely. Is it like that with Let's go? 

But even if it's like this, it's pretty poor. If you want to start the game again to try things differently, or you want to do something again, you can't load a previous game or create another save without creating an entire different account?