> You have imaginary rules about who should be protected in a city (based on seniority??)

Rent control is not imaginary (Any more than any other rules are), and yes, that is exactly how it functions, for the purpose that I have described.

It advantages senior occupants (Who are grandfathered into controlled rates), at the expense of junior ones, or ones who don't live there yet (Who are presented with inflated rates, for obvious economic reasons).