My parents paid for my education costs almost entirely (except for books/supplies). I would want to do the same for my kids, because it gave me much more flexibility in starting my career. They were of the belief that you shouldn't start your adult life in debt, and I frankly agree.
I should hit my fire number their senior year of highschool. If they receive scholarships, I will probably do "one more year" just in case. If they need help, I may move back my retirement date more. But it all depends on how hard they tried in highschool. If they are a C student, I would encourage them to join a community college or a technical school that matches their passions.
We’re working on front loading 529’s. The goal is to have enough in each to cover four years at a good in state university plus some buffer. Obviously they might literally do something different but it feels like a good baseline. Finishing this front loading is one of the items on our pre-FIRE checklist as the plan is to pull the trigger long before they’ll go off to college.