There should be an exponential backoff rule for failing propositions.

I don't like the idea because if you notice public opinion are slowly shifting on an policy you could purposefully propose it each backoff date to entrench it for like 8 or 16 years when public perception does swap.

I was joking, but my serious opinion on this is that direct democracy doesn't scale. For a country like Switzerland that is basically a small patchwork of villages up in the mountains it is probably fine, but for a polity of 39 million people and one of the biggest economies on Earth I should say it's a bad fit. Maybe for some local propositions.

... which is why it would be reasonable to allow local government units to implement rent control.

No, that doesn't follow at all. My point is about the scale of ballot measure not the effects. That would be for the State legislature to decide, in my opinion, not a State-wide referendum, is the point.