Exactly what I came here to say. My partner, son and I are looking forward to sleeping in your spare bedroom, and cooking in your non-spare kitchen, as well as setting up a play yard in your non-spare living room.
What you are both alluding to is exactly why the AirBnB model falls apart in most situations. You want your own thing, but you don't want to follow the law and respect others in the building (that have signed contracts in hand disallowing the practice). Every other owner or legal sublet in that building wanted their own thing. That's why they bought a unit or signed a lease.
That's not at all clear. The cost to resolve civil conflicts is something both basic economics and the law factors into regulation all the time.
Further: two very common kinds of contract we're talking about are with the state itself.
The first and most obvious is zoning, wherein the state promises to reserve some piece of land for a specific use, and private entities purchase that land with the expectation that it will only be used that way. It's for this reason that you can't build a hotel anywhere you want.
The second implied contract we have with the state are the codes and regulations governing residences. Long before Airbnb, residency codes had tenancy requirements.
Finally, the law itself has something to say about people who enter into contracts in bad faith, deliberately misrepresenting their intentions or circumstances in order to obtain concessions: we tend to call that "fraud".
