I never found anything on Airbnb to satisfy my needs, an hotel was always the cheaper and easier option. I'm always checking Airbnb as it has rooms in small towns along our way that would make our trip easier.
The very few places on Airbnb cheaper than the hotel usually required a 10-20km detour. And I'm not even counting the extra steps needed which make Airbnb a bad choice, like the message to convince your host to accept your booking, the need to communicate with him about your arrival time, analysing the photos to figure out if you have one or two beds, the house rules about cleaning etc..