Actually in my mind, Airbnb is always more expensive than a hotel. Each trip I end up checking both options and I'm amazed at how expensive Airbnb ends up being after you add all the hidden fees.

I think the main use case is for big groups and gathering. When you want to stay with 10 people. And even then, it's still more expensive than 6/7 hotel rooms (if you come as a couple you would only use a single room).

I think Airbnb manage to convince a lot of people that they are always a better deal than hotels. I see a lot of my friends never checking regular hotels anymore.