Well, to point out what seems to be the obvious, both are cameras, but one protects privacy more than the other, which seems to willfully give up to whatever authorities with little concern for the end-user. I use the former.
I am not an IT guy, so I am not sure what your point is: I don't have specialized knowledge others do not (I don't think I do) nor am I some sort of crazed hyperintelligent nerd who thereby can set up a UniFi Doorbell (mine didn't require PoE, I did have to swap out to a more powerful transformer, but I don't think that requires any more know how than installing a Ring Doorbell).
Ring advertises. UniFi doesn't Brand awareness probably plays a role here.