Regulation and involvement are two different things. Many cities are basically shall-issue when it comes to permitting. Others hand out variances like colleges hand out condoms.

I don't see how your response has any relation to what I wrote. It looks more like moving goalposts to me.

I'm saying that regulating zoning in an of itself is something all cities do but they do it to wildly varying extents (e.g. SF vs. Houston) and it doesn't correlated as directly with population as you're saying it does. It's also possible to regulate something (i.e. have zoning rules) but still take a very hands-off approach.