I think there are a couple of things that make jazz tend towards being more "difficult" for lack of a better word. One is that for whatever reason, jazz accommodates music with a very high level of complexity, and it's fun to go there and explore.
Another is that jazz no longer rules popular music, and is therefore not constrained to produce music that is "utilitarian" in the sense of being able to sell lots of records, fill dance halls, promote consumer products, etc.
I think there are a couple of things that make jazz tend towards being more "difficult" for lack of a better word. One is that for whatever reason, jazz accommodates music with a very high level of complexity, and it's fun to go there and explore.
Another is that jazz no longer rules popular music, and is therefore not constrained to produce music that is "utilitarian" in the sense of being able to sell lots of records, fill dance halls, promote consumer products, etc.