We need more graphics so we can them make them blurry again through FSR and DLSS to get good framerates on lower specs.
For real though, I do think diminishing returns is a real thing. Graphics don't have explosive improvements anymore, and since 2013 or so. Sure new technologies can improve visual fidelity, but it's not as meaningful or earth-shattering as it used to be.
If you honestly believe that, can you give us your full name, age, address and phone number here so we can be sure you are not a malicious person? Don't worry, it's for the children safety, so they can know who they are talking to.