You should never stop learning and school is a very good way to learn. If you don’t learn new stuff all the time your brain will literally stagnate and rot. It will atrophy.

Very few people are cut out for true self directed learning so, unless you’re one of the gifted few, structured and group learning is the best way to do it.

If you’re highly motivated anything is better than nothing. Find free courses, look stuff up, engage the academic world as best you can 🤷‍♀️