Pros buy new cameras about once a decade. And they don’t like drastic changes in UI. The reluctance to change and infrequent purchase cadence makes supporting the professional market a real bear. I understand that they typically sell their flagship models at a loss, but write the loss off as R&D.

I have to disagree about viewfinders and batteries being inferior. The viewfinder is an acquired taste. If you look at cinematography and movie production, you’d need to search for a long time before you found an optical viewfinder. And I just shot a 12hr production on a single battery, using the highest resolution DSLR on the market. No pro photographer will ever need more than a day of battery life.