I think people overestimate the degree zoning rules have held back new construction.
Construction costs are really high. And the legal costs still include lots of crazy environmental reviews, Indian artifact checks, variances getting approved.
To take one example, does this new law do anything about the rule that no more than 50% of the street-facing ground level of a development can be parking?
While parking requirements are getting eliminated and relaxed, some parking is still generally needed, especially for new mid to high end construction. Having them in the back of the lot means wasted space going to long driveways.
This is just a single example.
Here in 92107, we just have vast areas that have long been zoned multifamily but 75% or more of the lots remain single family. And even new construction tearing down old single family is about 2/3 replaced with larger single family, with most of the rest being two detached houses on 1 lot.
In other words, there just isn’t a lot of evidence people are maxxing out their lots now, and will go even denser if permitted. Parts of SF and LA are of course different where no-parking new construction condos will sell for $1200/sqft easy, so even with high construction costs developers want to max out.
San Diego just isn’t that expensive yet.
The only place where higher maxes would really come into play is oceanfront or within a 2 blocks. But these areas are limited by the height limit, not unit limits.