This. Compare two very drastically different games from the PS2 era: Dragon Quest VIII and Black.

The former still holds up well and looks fantastic for the most part, especially when you dial up the resolution on an emulator. Black... Does not, but was praised at the time for it's graphics.

The same thing is going to happen for games pushing "realism" today, twenty years from now. Between then and now a bunch of new rendering and modelling techniques will be discovered and new technologies will emerge which make the games of today look wooden and plastic. Maybe not in terms of raw polycount, but in numerous little details like fully rendered hair and clothing which moves and shifts realistically, soft textures having appropriate give (i.e. stand on a couch or in a puddle of mud, foot sinks in), rendering liquids as real volumes on the fly (i.e. dynamic rain which forms dynamic puddles and drains according to gravity), etc, etc.