In the last 30-40 years the cost to attend UC has gone up significantly (when I attended in the 90s tuition went down to $3,600/yr, it’s 5X that now), but the top schools are still world renown and the next tier have arguably moved up (UCSD and UCSB in particular).

I believe the greatest risk to California’s continued prosperity is the lack of affordable housing (which I would associate partly with Prop 13, but also just general NIMBYism). There have been a lot of efforts in the past few years to move towards higher density but I think we’ll need to wait until the next administration to see if this pro-housing approach is going to stick.