>Landlords usually require written notice to enter the premises, in advance, and cannot "lock you out at any time" without going through an eviction process if you have a lease.

Sure, in the same way that landlords aren't able to unfairly keep security deposits - they can and often do do it because it takes a lot of time and effort to attempt to get recompense after the fact, and the consequences even in that case are not significant enough to disincentivize them.