I don't think it's a one camera or system fits all world and though this thread will turn into the billion times discussed which is better 35mm or 645 issue the real answer is if you work professionally, whatever you buy, make sure it either gives you the look your after, is profitable or you enjoy it.
Hopefully all three.
That said, I don't see resolution as a factor anymore. Not with our work.
What I do see is a need for medium format to go to higher iso, to match the motion work we do.
You know it's all changed. There was a period where double the file size made a difference and for some it still does, but overall clients are looking for concept, style, look and options. I haven't had a client ask about file size in 5 years.
In fact the market has changed, at least in our business. Use to we shot for a specific media, or media plan. The creative brief "might" say national/international print run in periodicals, listing such, might add outdoor, usually mention print collateral with web as kind of a throw away.
Now you rarely get any of that. If you ask a client the questions do you want vertical or horizontal, shot to layout or wild, still or motion, mos or dialog, outdoor, or web, national or international, etc. etc., the answer is . . . yes.
Not that they'll use it in all of those functions, but they want the options in case it scores well in testing, or the big, big boss likes it.
It's that simple and with the crunch of time, numbers, costs of production, they don't seem to care if it's a 22 or 24 mpx dslr or a 30/ 40/60 mpx medium format.
Once again that doesn't mean you shouldn't use what you want or reaches your goals, but it will always be your goals, rarely your clients. They don't know if you camera has 12 or 16 bits, 10 or 14 stops of dr and don't really care. They care about the look, the use, the final costs of production.
Now coming from a still background and enjoying larger format cameras, when we shoot for ourselves or we shoot an editorial, most of the time I'll shoot the stills with our medium format cameras, because I want to, not because anyone is asking.
There is no absolute answer to any of this because everyone has a different business model.
IMO
BC