What I've seen in my city (LA adjacent) is the city can find really creative ways of making adding an ADU very expensive. On my block the same contractor built 2 different ~500 sq ft units on two different lots. They both were a garage tear down replaced by a 1 bedroom unit above a garage.
The first unit was done right after the law change allowing ADUs, and cost ~140k. The second, started 18 months later was ~270k and the owner had to pay for things like repaving the ally and upgrading the sewers.
So even the small steps are being impeded.