> I know of many people...
Visible benefits; invisible costs. Great politics.
Who you don't see are the people outside looking in that want an apartment but can't find one, or can't afford one, or need to sign a new lease at a very high rent.
Rent control doesn't unequivocally help current renters. It also keeps them stuck in one place for a long time, even when it's not a great fit for them.
And pretty much every economist says rent control raises rents and lowers quality overall, hurting those trying to move in.