if its really that incredibly powerful, bare minimum is 4k resolution 60 fps for all games ???
The thing is, nothing is infinite in this world.
You have a set hardware (high end PC or any console), you develop a game for it, you can choose to program it at 1080p 60fps with quality graphics (ray tracing, high res textures, long view distance, detailed environment without corridors or hallways to mask texture loading, or you can choose to program at 4K 30fps with lesser graphics details, shorter viewing distance, lesser onscreen objects etc.
With a fixed HW, trying to program a higher res game (4K) as oppose to a lower res game (1080p) will always result in a trade off of some kind. The same argument goes for 8K against 4K.
It ultimately depends on the game and what the developers can squeeze out of the HW. For FPS games, framerate is probably more important to some gamers so it can be designed with reduced graphics quality to push 60 or 120fps.
For RPG games, you don't need high framerates so developers can concentrate on much better environment graphics and character models etc.
Even with current ultimate PC setup running games at 4K 120fps, some people will still complain it can only run the same game at 8K 30fps with lower graphics texture. And when it finally comes time running 8K 120fps, others will complain it can only run 12K 30fps.
Basically it's a never-ending quest.