Jazz doesn’t, and shouldn’t appeal to everyone. It’s like a very rare and fine wine, which only a few appreciate.
Music theory isn’t necessary to appreciate jazz, nor is it complicated. Jazz uses the same 12 notes used in Classical music. So how is it musicians created a music, that on the surface appears, complex? But is it complex, or simply your ears aren’t tuned how to listen? That’s why I said, many don’t understand jazz, which has no bearing on whether they like it. Compared to jazz greats, I’m a very mediocre jazz musician. But still, it’s been a journey I’d not trade for anything.