As someone who works as a 3D artist in games.... I feel like there's very little that distinguishes the PS4 gen from the PS5 gen besides higher specs.
There were pretty huge gaps in the past. Like when we went from the SNES gen to the PS1/N64 gen, pretty big gap. We went from mostly 2D games into a 3D generation.
The PS2/GC/XBox gen increased the potential polycount by a huge margin, lighting was more of a thing(even if it was largely pre-rendered or prebaked for most games), bump maps in certain games(mostly X-Box I think due to its comparatively higher specs). Well there was a huge visual difference either way.
In the PS3/360 gen, games had normal mapping, far higher poly count, much bigger use of dynamic lights. Huge visual leap from the previous gen.
In the PS4/XB1 gen, well not that much has changed really from a technological standpoint. It kinda all ticks the same, specs are just higher. This is the gen where Physically Based Rendering started to become a thing, so games were able to look a lot more realistic and lighting in general became a lot better.
Now in the PS5/X-Series gen.... honestly they are just beefier machines. Real Time Raytracing should have been the new paradigm shift, but I've seen how lukewarm the reception has been to that and I'm not really convinced that the consoles have the specs to really usher in a new era of real time RT. I haven't really been paying attention to the capability of the next gen consoles though. I think people are saying the PS5's Navi card is about as good as a 2070/2080? Which struggled to run RT capable games at high frame rates. But I don't own a PS5 so no real comment there. Also a lot of the current 'RT capable' games don't really run a proper full raytracing solution, it's like a weird hybridized thing. Cause full real time RT just wouldn't feasibly run well. Metro Enhanced Edition does sound like it's gone full RT though, but that's PC only. And it had to be a whole separate version because it's just the nature of how RT runs. Can't have proper RT happening if you got all your shitty baked lights still in and about along with the usual smoke and mirrors.
Get a glimpse of new and improved real-time rendering features currently in development.
www.unrealengine.com
The current UE5 demos are showing off some impressive looking shit, so maybe there's a software solution to the whole RT conundrum, but it looks a little too good to be through so I'll believe it when I see it. And well, just because UE5 can accomplish it in their own theoretical best scenario doesn't mean every game will look like that anyway.
I need a decent PC to work anyway, so I can't say I'm super sold on the 'next generation'. Heck, even Microsoft itself doesn't seem to be banking that hard on the Series-X, it looks like they are more interested in selling the Game Pass as their true 'next gen console' in a way.
I'd like for real time raytracing to become normalized at some point though. It would make work easier. Though I'd also very much like to leave the industry I work in...