State parks that cost $10 to visit each one, when there is often nothing in them? Nah, that state is great at getting at your money and wasting it on corrupt government.
It's regular park not an amusement park. I don't know what you want "in them" other than hiking paths, picnic tables, parks free of trash/debris, respectable camping grounds, running water and toilets. Maybe you're not a nature person, but that seems worth $10 to me.
I'm not sure what your expectations are, but I've done a lot of hiking and camping across the USA and CA does it pretty well.
Typically the fees are proportional to the facilities provided. CA often provides well maintained and regularly cleaned flush toilets and even hot showers at the state parks w/campgrounds, this is far less common in other states.
CA does it so well I generally prefer camping there over staying in hotels. It's typically too much of a hassle elsewhere in the country, where KOA "campgrounds" are often the only options with such facilities.
I've also done a lot of day hikes in CA state parks where there's no fee. You just park at a trail head and off you go, and these sometimes even have pit toilets at the lot, still with no fee at all.
The local organic produce is very good too.