The jazz musicians who I knew up close and personal, were driven ((unfortunately, not to make money) they were driven to create.
A musician I had not seen or heard for a few years (we were friends) came back with a new sound that I was totally unfamiliar with, that was spectacular; he was hard bop improvisational. When we see or hear Jimmy Smith do his thing, he makes it look easy; all pros make their thing look easy, maybe it is for them.
The only thing I know about hard bop improvisational jazz is how to listen to it, and I claim to be able to qualify how good it is. On our first outing (I say "Our", because we renewed our friendship, and he moved into my apartment) at "Helens Black Eagle", a club that cherished "improvisational hard bop" we wowed the crowd; they were mesmerized.
During that Summer, we had a lot of fun and repeatedly wowed crowds. That was in 69, and the only verification I recall was a write up about his performance on center stage at the VP Fair we have here in St. Louis.
Many years later, I was talking to a musician telling him how good my friend was, and he responded; "He was good, but he wasn't that good". The musician I was talking to, was on par with Horace Silver, not one easily impressed.
Maybe he didn't hear him after he got that good, I thought to myself. That was when I searched for every note my friend had recorded, and I only verified that "He was good, but not that good".
The music he was playing that Summer was new, plus it had not, nor was it ever recorded; consequently, I have nothing to prove he was "That good".
While I can not judge all "improvisational hard bop jazz musicians" by my friend, being on center stage, and mesmerizing a crowd of people is what drove him.