SLRs’ problem is they’re big, bulky, annoying.
But… phone cameras’ problem is you can’t take a picture with just one hand (or it’s really hard, or you’ll drop the phone, or you’ll miss the shot). I think that is the main reason while more pro photographers don’t use phones (and not resolution, or zoom, or dials, etc.)
I’m not a pro but a serious enthusiast, and having to use both hands and no viewfinder to take a picture is a deal breaker for me.
I wonder if there’s an opportunity to either make a lighter camera based on phone tech, but that can be operated with one hand, or to make a (serious, non gadget) accessory that let you take pictures with one hand, using your phone.
The models that come out of Canon or Nikon are really depressing, nothing is ever new. Fujis are much more interesting, but still quite ordinary. A lighter and flatter X100T would have been fantastic, but instead, the X100F is bigger and heavier. Go figure.