They aren’t “extracting wealth” from communities any more than Booking.com does. In fact, AirBnB creates wealth. A person renting out a room on AirBnB is economically better off than if they didn’t.
Building something creates wealth. Changing the channel through which payment occurs doesn't create wealth. The host's revenue comes from displacing hotels; the guest's savings come from increased rent for other tenants. If you consider the negative externalities imposed on neighbors, there'd be a stronger argument that AirBnB destroys wealth.
Incorrect. They are removing apartments from the supply, thus raising rents. A couple airbnbs in a huge apartment building have many external costs that are carried by the other tenants.