I’ve known a LOT of people who were persistent as can be, and did the hustle and grind day and night, who never caught a break. I’ve also known a fair number of financially or artistically successful people, people known for their work, who honestly got advantages along the way that simply weren’t available to others. The secret to success is to be given money by your parents, or catch a rare wave. You want to be persistent *at being ready to catch a wild wave*. That’s what you practice for, apart from personal enjoyment.
Not at all disagreeing with that - though I think there's another angle to this that often doesn't come up.
But first - there's no getting around the leg up that parental support is. Not necessarily actual "given money by their parents" - but in a sense, "in kind" I guess it is. Getting started means at least minimal gear, getting good usually means education - lessons, coaching, school.... And the younger one gets serious the better - this usually means as a teenager, playing in school, playing in bands - spending gas money and chewing up drumsticks for a billion playing activities that generate next to no revenue. And when done pretty fully leaves little time for sports... nor anything like part-time "teen" type jobs. (I knew some serious young players that had to work part time jobs, while going to school to say, have a car - and they did, but it slowed them down.... made it harder.) So certainly, taking advantage of every advantage is a factor.
But the main thing I wanted to touch on regarding persistence is the inability of many players to assess the attainability of their specific goals. Of course setting goals is a good thing. But when shooting for a very long odds goal (and most goals in music are exactly that), one needs to really assess how long the odds are. IMO one way to improve the odds is to pursue many parallel, related goals concurrently.
I've seen so many folks shoot themselves in the foot by deciding their goal was to succeed in this kind of band, taking a specific path. They start with the sort of band they want to have success with - and that's it. They just work at that - they persevere with that, till it peters out, then do it again with another similar band. At first glance, that might seem like a focused plan. But in reality - it greatly reduces a young player's opportunities to gain experience and just get better.
Whereas getting more irons in the fire invariable means playing more - with more people, more settings, but most importantly.... more. But of course, the mindset required approach it that has to allow for any of those alternate paths to become dominant for awhile. Frankly I don't know that I've met anyone that survived for long pursuing this as a career with the idea that "I'm only going to play the music I want to play in the kind of setting I want to play it in... period" - with anything outside the being a distraction. And that IMO can be pursued until one is blue in the face with very very very long odds of working out.
So many players I've worked with over the years tended to have goals with a wider focus.... "I want to be able to play drums with good players" - "I would love to have a career playing drums". A broader focus hopefully allow for a wider range of opportunities to be caught - but in the meantime, it boils down to first playing with anyone that will play with you, and then pursuing and accepting in and every gig that pays money...
Will persevering in that way insure being able to make a living playing?.... Oh, no. There's still the issue of way too many aspiring professionals and way way too few jobs - a situation that has done nothing but dramatically digress in the past 20 years or so. So competition is simple huge. So being better is more important than ever - and better meaning the whole package - playing ability, musical sensibilities, people skills, versatility, etc. etc. All this path does is focus that perseverance down a path that has a greater chance of success - than the more "win the Loto" approach.