There
are autodidacts who can go a long way with a big library (or nowadays: sci-hub, b-ok, MOOCs) and their own self-directed study. But if you haven't started on that path before finishing high school, it seems extremely risky to assume that you can start doing it instead of attending a university. Further, if you're already self-motivated and learning on your own, you're probably going to have a lot of (intellectual) fun attending one of the more rigorous institutions, learn faster with access to proper labs for experimental sciences, and fill in gaps that you might have tended to neglect with pure self-study. The credential will also be a big help later whether you want to go on deeper into research or find an "ordinary" full time job afterward. (College degrees are still economically worth it
for those who complete the degree. If you can learn degree-material on your own you aren't going to be one of those sad cases who takes on student loan debt without graduating.)
I hated school before I reached the university level. I maintained good grades but I was usually bored and learned most interesting things on my own. A university was the first place I found a majority of fellow students who were straining forward to learn due to interest in what they were learning. It makes the experience far different from being with people who are just being goaded forward by a teacher or evaluating everything in light of "will this be on the test?"