This is a very interesting thread with lots of good points. I am a recovering Gear Addict. In my 79th year, I have owned nearly every system there is - from full plate cameras on up. My formative years were spent with Rollei TLRs; later I mostly shot with Canon (remember the F1?) and after a spell with Hassy, Rollei 6008 and Leica R4 I went back to Canon to make the digital transition. I owned Leica Ms, both film and digital. The only significant brand I've never used is Nikon - though I'd like to. But see my second sentence above....I'm supposed to be recovering.
As Paul Spinnier says, age does change the equation. Even so, I have been a Phase owner since the P45 fifteen years ago and still enjoy using it more than any other system. Yes, it's heavy but the image quality and DR is, to my eyes, the best. Do I really need it? No - though I do make large prints and like the ability to crop massively and still have great image quality. (Ironically, though, my all-time best selling print is a 36 by 24 inch landscape taken with a Leica M9!) But as others have observed, most people can't see the difference between an IQ4-150 file and Sony full frame file even at very large sizes.
Today I keep the Phase system with a bunch of lenses and a Sony Ar3 with just two "G" zooms, 24-15 and 100-400. That is my travel/back-up/walk-around system. It's a good system... but.. I really don't love using it. It's very much a tool, whereas the MF still gives me a thrill.
All this is say to the OP that the right camera is not simply a matter of specifications or cost or even applicability to your subjects and mode of shooting - there is an emotional component that if it's right, will give you pleasure every time you pick it up.
(PS - I lied in my second sentence. I just bought a Leica Q2 Monochrom...)