Hi,
I tend to agree. So many makes and models of FF out there which do more than enough for most people.
I think I could get by better with a 60 MP FF than I am doing with a 50 MP MF. Even down to the Pentax 645 lenses I already own. When I shoot MF, I tend to do so manually focusing and on a tripod. And there are adapters from P645 to just about everything out there. Many offer shift and some offer tilt as well.
And the P645 lenses still tend to sell on the used market for very low prices. So there is an idea for you.
In my case, no Nikon 60 MP class bodies yet. And that's important as I have many Nikkor lenses around here. So buying a Sony, say, doesn't really help me much. So I'll stick with what I have. And I have put off buying a 100 MP MF for what has become quite a while now. And, still no rush. My largest print size remains 16x20" and so no rush until I happen to update that.
And my reasoning for all this revolves around cropping the native aspect ratio to 5:4 for those prints. And I lose fewer pixels coming from 4:3 than I do coming from 3:2. And I print on paper at 360 PPI and textiles at 300 PPI.
As it is, my highest resolution FF camera has 16 MP so moving to the Pentax digital MF made the most sense from a cost standpoint. And I believe it would cost me less to add a 60 MP Nikon than to add a 100 MP Fujifilm. Only time will tell about that,.of course.
Anyway, the bottom line is maybe think about adapting MF lenses to your FF and so gain the benefits of tilt and shift when needed via an adapter.
Stan