Well, but why those don't go out and buy a flat they can rent in AirBnB instead of sub-renting someone else's? Most rental contracts explicitly forbid sub-renti

Well, but why those don't go out and buy a flat they can rent in AirBnB instead of sub-renting someone else's? Most rental contracts explicitly forbid sub-renting and I'm pretty sure these cool people don't pay taxes on the money they get from the short-term tenants. This is a greeeeey area.