The rats and all geometry that spawns into a scene has to be drawn on screen.
There are 100s of thousands of them. (300,000 to be exact, up from 5,000 in the last game)
The CPU has to call for the GPU to draw them.
Thats a draw call.
A game might not be GPU intensive but it could be CPU intensive which could lock it out from being on a lastgen machine.
Sure with enough tinkering and optimizing you could probably get any game to run on anything, but lets be real with budgets and time.
If all we had to worry about is scaling to GPUs set everything to potato quality and voila Switch/Mobile port.
But some parts of the game, especially CPU side things are much much harder to scale down.
The same could be true for a game like Plagues Tale which might not be the most graphically intensive game, but it could be utilizing the CPU beyond whats available in the Xbox One.
The "looks nextgen" argument always bemuses me.
99% of the artists working on these games can make well well beyond spec scenes with ease as in scenes wont be rendered in frames per second but second per frame.........but balancing and optimizing basically forces them to scale down stuff to work all
(read as most) of the time.
Yes with a large enough budget and a large enough team you could optimize and optimize again till your assets are near ground truth....but not every studio has that, and not every studio even thinks its worth the effort to do so.
Dead Space Remake might not be the most stunning game out there, but it looks good.
Could it run on a PS4....i dont know what its doing under the hood.
Plagues Tale Requiem is being made by a relatively small independent studio, and their game looks stunning, could they have squeezed the game onto Xbox One.....with enough time and effort im sure, we have seen some switch ports that dont make sense......would it be worth it?
Or just enjoy the extra leeway you have with nextgen machines?