I bought the X-Pro2 for the optical viewfinder, and that's what I use it for most of the time. A single prime lens, an X-Pro2 on a strap, that's quintessential photography to me. Thus, for most situations, it's 100% OVF.
For zooms or very wide lenses, I use an X-T3 with its electronic viewfinder instead. The only time I use the X-Pro2's EVF is when I go on an explicit photography excursions with the 16-80/X-T3 and 70-300/X-Pro2. But those occasions are rare. (As a fun diversion, I occasionally use the 70-300 with the OVF for tracking birds. It's kind of useful to be able to see outside the frame when you try to keep a small, fast-moving object in frame)
On the other hand, I tend to use the back screen kind of a lot, maybe 50/50 with the OVF.