I would assert that The high efficiency of Class D amps along with optimizations with power supplies for that including noise suppression enables integrated amps in general to push the limits and please even more people. Having been around a while and experienced a lot in this area, that is my observation. Noise levels with Class D amps many years back was a common problem but need not be anymore.
So more is always possible with separates. It’s not a slam dunk though in all cases. In fact it’s probably harder than ever for separates to distinguish themselves in any way meaningful to most home audio users.
A hard core audiophile determined to always push the limits no matter what will still not stop trying to do that. Some will succeed. Others may not. My point is personally I no longer feel that the return is worth it for me. So I turn in my audiophile membership card. Call me an enthusiast, at least for now. 😉. I will always be a music lover.