I've taken exactly 1 picture with my Nifty RFifty, which might be 1 more than I shot with my EF version.
I've always owned a 50mm lens. Cheap way to get a good, fast lens. But I almost never, ever, actually use them. Fair or not, in my mind they're just too normal. If I change lenses and move my feet, I can get a more interesting perspective. Another reason is that I don't use primes at all anymore. I shoot with zooms now and I'm surprised at how many shots I make near 50mm. I view that as lazy, but 50mm is probably more practical than I give it credit for.
The real reason I keep one around these days is as a setup lens. When I'm sitting at my desk, fritzing with the settings on the back of my cameras, my nifty fifty is the best lens for that.
Oops. I just looked at the EXIF on this shot and I made it with an R7. That gives me an 80mm FOV and perspective.