There are other aspects beyond simply being more permissive. I recall reading for example that property transfer tax is remarkably less on bare land, enough so that when travelling in Japan you will regularly notice bare lots for sale, as it is beneficial for the seller to tear down a lot before they sell it. This sort of thing encourages churn of housing, and coupled with liberal zoning, enables an accelerated increase in denser building. Tbh it probably encourages lower construction costs since more people are doing construction.

IMO in this whole conversation, whether discussing any jurisdiction not just japan, impacts of zoning is an over emphasized and tax policy under emphasized (ie. almost never discussed).

From what I remember, Japanese zoning allows small shops (there's a size limit) in any residential zone.

That means no car trips when you run out of bread or milk.

Smartest property of that zoning system IMO.

That's a big part of it. They also do zoning mostly at the federal level, meaning local opposition isn't relevant.

Sometimes permissive zoning laws don’t actually encourage positive urban development outcomes.

Example: Texas

Zoning has to both exist and be well-designed.