A new bill seems to come up every few years (2016 bill moving smog exempt to 1981:
https://leginfo.legislature.ca.gov/faces/billNavClient.xhtml?bill_id=201520160SB1239). It's free money for the state so, there's really no incentive to change the current law.
To understand just how few cars are affected, check out this (from a 2016 article,
https://www.motortrend.com/news/california-bill-to-move-smog-exception-from-1975-to-1980-progresses/): Only around 162,000 of the approximately 27 million cars on California roads are exempt under the current law, according to the Association of California Car Clubs. The change is said to only affect half a percent of vehicles.
I love San Diego but, CA has a lot of (easily fixable, theoretically) negatives.