But, how many tried gaming and then bounced off/quit after a fairly short time?
IME, LOTS. Of the gamers I played with into high school, I'm the only one who stayed in the hobby. I don't know anyone in person that I gamed with who is still gaming. None of my friend/acquaintances from back in the day are still in the hobby.
There seems to be this idea that if people just tried it, they'd like it. That's very much not my experience. The overwhelming majority of people try it, play for a bit, then move on. Which means the number who try it, like it enough to try running it, and then stick with running it, is a very, very small minority.