I think the marketing of prop 13 was old people getting kicked out of their houses.
But I think the majority of the tax avoidance goes to not-old-people, like immortal corporations that can own the land forever.
EDIT: random link - it seems like residential owners don't benefit anywhere NEAR as much as commercial, rental and industrial entitites.
https://youngamericans.berkeley.edu/wp-content/uploads/2023/...