We could build more homes on golf courses, we could build affordable housing, we could build up, we could get rid of parking mandates. All of that would cost The Boomer, and so is forbidden.
We could build homes no golf courses and it still wouldn't matter because only the rich could afford to live in them anyway.
The law simply needs to be updated - though it's basically political suicide to attempt it - to only include primary residences of a certain relative value. If you have three houses and a mansion, you should be paying way more tax.
BTW many other states have Homestead Exemption that only applies to homeowners, retirees, widows, or veterans. Unlike Prop 13 they were designed to specifically help those groups while making sure the state was still able to collect tax revenue from those not in that group.