I'm afraid you're wrong: there are many, MANY supply and demand denialists around, who think it doesn't apply to housing. Believe me, I've argued with them. They see that brand new housing is more expensive than the decades-old housing it replaced, and go, "See?? It didn't help the prices at all!"
> Zoning regulations aren't usually arbitrary
True, in many cases they were designed to keep out undesirables, like people who are poor, or non-white. That's not arbitrary, it's intentionally bigoted.
Nobody's suggesting dumping factories into residential areas, or relaxing basic safety standards. That type of zoning is absolutely fine.
The biggest reason is political, that people have NIMBY tendencies: yes there needs to be more housing somewhere, but put it somewhere else please. I don't want to have to worry about parking or see unsightly apartments on my block.
I don't dispute that infrastructure is a concern, but it's not a blocker. Cities growing quickly isn't some unfathomable phenomenon of the 21st century, the logistics can be handled if people want it politically.