Camping in CA public state parks was not really pleasant even 20 years ago. Noisy carousing, loud music, drinking beer and dropping trash, late into the night, dare I say it, (probably half illegal) Mestizos. Sorry, I go camping to get away from people and all those annoyances.
I camped with our kids about 25 years ago at Lake Del Valle. You described the experience exactly. Surrounded by parties, noise, “music,” drunks until WAY past lights-out at 10 pm. We never went back.
Our Bay Area town’s parks are always overrun with Mexicans and their loud parties, too.