I don't recall PS4 Pro having any performance (60fps) modes besides TLOU and any other PS3 to PS4 ports. Everything else was just base PS4 FPS but at checkerboarded 4k

Plenty had performance modes. Some games got rid of them but loads of games had them, they weren't advertised but they were in the settings on loads of games. Some were options to up to quality mode over a base mode like FF14. God of war ragnorok and Horizon Forbidden West were the most recent I remember. The games that didn't would improve in frame rate if you locked the console to 1080p, for example it had to be done with Cyberpunk, for fuck all difference it made to its brokenness it helped with fps. 

I just googled Horizon Forbidden West on PS4 Pro and there is no reference to any performance mode, it seems locked at 30fps on the console. 

Generally speaking the performance modes you're seeing are likely either just uncapped frame rates or just more "performant" modes that are used to more consistently hit the target FPS the game is running at on base PS4.

FF15 was patched to have a "60fps modes" but that runs in the 40s most of the time.

https://www.eurogamer.net/digitalfoundry-2017-can-final-fantasy-15-hit-60fps-on-ps4-pro

PS4 Pro did not meaningfully have 60fps performance modes aside from a select few games, the hardware is simply not built for doubling the PS4s base frame rate unless a game already had plenty of headroom to spare (ala PS3 remasters/ports)

I know The point of this thread is to compare current and previous gen games, but to be fair, I remember how awesome Megaman looked on NES running smooth at 50Hz.

Also a thing that haven't been discussed, are the game engines that aren't optimised for consoles. Seeing how low the system recommendations are on Steam for rather new games, so based of specs, you'd expect them to run as intended on PS5. BUT, PS5 has unified memory architecture, which means that it's behind your mid-range gaming PC on terms of RAM, which is likely to Renault in less performance, If they don''t optimise the code.

Some games have proven that it can be done, it just isn't being done. 

The devs are likely to take the easy route and split the RAM the way they see fit and use it as X amount of VRAM and Y amount of RAM, instead of dynamically allocating it depending on the situation. Also, nobody's going to notice if you have a grass or two missing to save memory, so it's a matter of optimisation. PS2 and PS3 were the lead platforms for most games they had, so they ran well and looked good because they were optimised on the systems, but with PS5, it seems PC is the lead.

There are some very simple reasons why the visual jump isn't seen as significant from a technical perspective.

It's all about how graphics are being rendered, I won't go into it to much...

But to make Playstation 3/Playstation 4 titles "shine" developers used a TON of baked details for things like lighting and shadowing which came with a minimal corresponding requirement for more hardware resources.

Today? It's all dynamic effects in real time.
Environments are more reactive and dynamic because of that visually, but when looking at a still image, it's not going to showcase massive differences.

Dynamic effects require more resources. It's that simple.

What dynamic effects? Forbidden West Burning shores has loads of those and it is easily in the top 5 best looking games ever. But to prove your theory wrong, have a look at this below which pretty much sums up where the dynamic effect are gone, much like the graphics themselves. 

Or Red Faction destruction, Battlefield bad company etc Games are far more static than ever for the most part and when devs who try to add dynamic stuff that aren't Guerilla, Nintendo or Kojima Studios they are disasters like Dragons Dogma 2. Tears of the kingdom is a perfect example of setting a graphical goal to add in the new mechanics you want, a clear down grade over BoTW which is odd for a sequel in gaming but THE RIGHT MOVE.

...SORRY TO BE SHOUTING BUT CAPS LOCK WAS ON AND I'M NOT GOING EDITING IT. 

It's more "high res textures" that require more resources, not the dynamic (environmental) effects.
From Dust was a ps3 / 360 game with total terrain deformation. It had a lot more going on than modern games.

But true, dynamic lighting, shadows, reflections, those dynamic 'effects' are all very costly. And those have huge diminishing returns between pre-baked and doing it for real. Plus the pre-baked lighting was always set to the ideal lighting for the scene while dynamic real time lighting can look worse just because light sources are in different places.

From a technical (software) perspective the jump is still there, yet from an end result perspective the jump is more like "sometimes it looks better if you pay attention".

So yep, you have to see it in motion and pay close attention to see what is improved.

Forbidden West is actually a good example.

Some of the effects were paired back like Bokeh DoF in favor of a Guassian blur effect.

And then you have the pre-calculated lighting, the Playstation 4 has multiple pre-calculated light placements/colour/shading to simulate different times of day, where-as the PS5 release deploys global illumination, albeit with limited light bounce.

And then we touch on things like the removal of the screen space reflections and the volumetric clouds being significantly paired back.

And that's the point I was making.

***

As for your Youtube video it showcases games like Skyrim... Again, I think you have misconstrued dynamic gameplay elements to rendering elements.

Skyrim is a game with heavily baked lighting, shadowing and effects, this was due to constraints to the 7th gen consoles. - But Skyrim did deploy *some* dynamic effects like shadowing on "active" objects such as arrows.

If Skyrim was released today it would have a fully dynamic shadowing system with global illumination with multiple bounces of light. It's that simple.
And it wouldn't be able to run on previous console generations because of it.


***

And Zelda? That's also an interesting take.

Let's take the Chemistry Engine in Zelda as an example, it's very impressive in how it showcases itself. - But we need to keep in mind it is also very basic.

Every single object and material in Zelda has a set number of "properties" - Which is PRE-CALCULATED. - Those properties are changed when it comes into contact with another material with it's own set number of defined properties.
So for example when the fire-material impacts upon wood, the wood then set to "burn = 1" on the object, then the engine draws a basic fire model to simulate it burning.
This isn't actually computationally intensive, it's just development intensive as it takes a long time to build all the objects and assets with the right material properties and have them interact in an intended way.

Physics interactions are only active when objects have been "influenced". - Objects otherwise don't run physics calculations... As the hardware and engine would slow to a crawl.

This is nothing new, the OG Xbox was doing this stuff with games like Half Life 2.

The limitation? It's a very long development process.

The other part of Breath of the Wild is the simplified details... The Clouds for example aren't volumetric.
The lighting in Breath of the Wild uses light probes through the environment to collect colour information and transfer that to other surfaces, there is no simulation of light bounces, just some approximation of what it thinks the colour should be in an area.

We also need to keep in mind that texturally and geometrically Breath of the Wild is also very very basic and will use sprites at every opportunity where it makes sense.

But that is just a testament to the prowess of the developers to use those techniques to maximum effect.

A more modern release of Breath of the Wild (I.E. Think: Switch 2.0) would likely deploy Ray Traced Global Illumination for the lighting.

False. Pre-calculated lighting, shadowing is significantly less intensive (Almost free) than Real-Time Global Illumination.

Using Cube Maps for reflections instead of Ray Tracing? Again. The RT is orders of magnitude more intensive.

The issue with pre-baked is that it takes time.

We as gamers constantly demand better graphics, so developers make better assets like Texture Maps.. So something has to give to ensure we fit inside developer and monetary budgets... And one of the easiest ways to do that is to throw dynamic lighting, shadowing and reflections at the problem rather than have artists spend time working the assets.