I think the value-add of Airbnb in cities is the neighborhoods you can stay in.
I'd say that's similar for the other services too. I used VRBO for my last trip and I got to stay in Vauxhall for only slightly more per night than the MOXY I stayed at near the end of the trip. The MOXY, however, was much further from the city and thus more of a hassle (not to mention that hotels closer to Central London were much more expensive).
In any case, I might try Airbnb for a domestic trip at some point. (I didn't for the last trip because of their forced currency conversion and 3% FX fee.)