However, your average Airbnb apartment and the average hotel room are nothing alike. Most of the Airbnb's I've used are far closer to what I'd expect in a suite at a moderately nice hotel. If you compare that, the price of two diverges immensely.
Just recently I spent three days on a 60 ft barge on the Seine in Paris opposite the Louvre. There is really no comparison to even a high-end hotel there (and I've stayed in several in Paris), but it was maybe 30% of the cost of a comparable experience I'd find for that location and living space size.
I could be an abnormality in my usage of Airbnb. I actually pay about what I'd expect to for a standard hotel room. I just expect what I'd get in a suite minus room service.