That's just how it goes. Studios make alot of money and stick to their guns. It wasnt always like this.. I think the rise of metacritic may play a factor. Most of the current big budget gaming industry can be traced back to Resident Evil 4. All you need is one studio to jump and others will follow.
increased development costs have an effect on the risk studios/publishers are willing to take. the more money you spend to make something, the more certainty you want it will sell a base X number of copies. it's that simple, and it's largely the reason why you see so many sequels, remasters and remakes instead of burgeoning new IP (outside of indies and shyt)
graphical arms race contributed heavily to this. studios be doing stupid shyt like fukking spending millions of dollars on character polygon counts and useless shyt adding peach fuzz, hair follicles and detailed eye irises to character models - shyt that only basement dwellers care about and will notice for two seconds when they zoom in on characters - instead of innovating or at least iterating on the application of gameplay mechanics and gameplay feel - got dev time and costs through the roof
i get it, it's easier to advertise graphics than gameplay feel, but chasing hyper-realism got this industry super stale