You don't understand anything about either term you used.

Populism is not and has never been a right wing thing. Populism is the idea the the people should control society and their interests are more important than abstract concepts like the economy which benefit primarily the elite. The term has no political leaning.

Rent control is not a leftist policy. It's neoliberalism. Neoliberalism is not leftist in the slightest. It's simply a rebranding of right wing policy.

Rent control is populism.