I asked a british dealer about the ratio enthusiast vs pro photographers, and they've seen a sharp increase of enthusiast photographers in recent years. In Europe it's not only the highest end products from Phase One that gets all the attention though, the CFV-50c has been very popular for example much thanks to its pricing.
The preowned/second hand market is great too, so those interested in playing around with MFD does not need to spend
that much, it's a bit sad that the latest gear gets almost all attention.
If you care about more than resolving power and DR, you can find much joy in using MFD. The reason I use MFD is to be able to shoot in "large format style" (using a Linhof Techno) without having to mess with film. High image quality is only one aspect of that, movements and the slow pace is an intergral part of the photographic process.
If the trend continues and MFD end up being about resolving power only, and movements you fix with focus stacking and perspective correction in post I might just start shooting film in the end

. My purpose with photography is trying to make art, and to make art it actually does matter to me how much of the photographic process that is a craft in the field and how much is post-processing at the computer.
When at large format film, I'd like to say that it very quickly would become more expensive than the MFD gear I have. Shooting large format film has some pretty high running costs.