This is empirically not supported. Relaxing zoning rules works extremely well.
Look at Japan, look at any metropolitan U.S. city that has actually leaned into it. Europe has had mixed use zones for effectively centuries and is not the dystopia that NIMBYs proclaim will appear in the absence of zoning.
It is unpopular because we subsidize the lives and assets of people who “have things” through zoning policy that they make.
Taxing land works better. Look at Japan where property taxes encourage development.
Up to a point. Yes, it is nice to mix housing and retail and the like, and some zoning laws prevent this. But you have to look back into the 19th century before zoning laws existed and you had things like slaughterhouses opening in residential neighborhoods. Zoning has good reasons to exist.