I would be careful. As a young child I was allowed to self-direct many aspects of my education (Montessori schools, permissive parents, etc.), and as a consequence I immaturely neglected many "boring" activities like learning math facts and spelling. Especially in math, shaky foundations have plagued me ever since, and I still have deficits in that area, which I very much regret.

The problem with letting children self-direct themselves to a high degree is that they're immature and ignorant. The world is a much more complicated place than it was hundreds or thousands of years ago, and many of the skills and activities they need to master are essentially invisible to them, so they need a lot of guidance and some external motivation to gain them. For instance, they might end up finding a lot of joy in advanced math, but they're going to have to slog through some hard stuff to get there. If they don't, many opportunities will be closed to them.