That’s not really true. It’s perfectly possible to directly regulate, prohibit and/or tax nuisances and externalities directly without zoning.

Ok.

So basically zoning but pretending it's not called zoning.

Zoning means central planners literally draw a map saying what goes where, and generally make all kinds of aesthetic decisions to go along with it. There is a big gap between that level of micromanaging land use and regulating against nuisances.

No, since this alternative allows for an apartment building with a couple of shops on the ground floor (normal in most of the world), and any other reasonable mixed development.

No one is suggesting heavy industry should be allowed in a residential area.

A set of local laws that says "heavy industry isn't allowed in residential areas" is a zoning code

It's a planning / permitting code, but the distinction from a zoning code has already been discussed in this thread.

And to quote one of the other commenters in that other part of the thread: "That’s zoning with a different name."

If you tax unequally, depending upon location, then that's just zoning with another name, except the rich can ignore it.

But the key is who regulates, prohibits, etc.

If that power is local, NIMBY always wins. These decisions must be made at the state level. Cities are way too fractured into myriad municipalities competing for jobs and "quality" housing.

The power is with rich locals.

I'd assume state power is with the same rich folks, so it's still NIMBY, but the state can force it on poor locals. Woooo

Why? If people choose to live next to the incinerator that's their choice. You can also have "industrial only" zones for stuff that's pollution emitting, but most things don't need that zoning. Example Japan: https://www.youtube.com/watch?v=wfm2xCKOCNk