Did Leonardo's art suffer for being done for patrons? Maybe, who knows? What would he have created if he'd had some kind of Renaissance-era version of Patreon, with a thousand people willing to give him one measly florin a month to keep doing whatever he wanted to instead of painting the heck out of portraits of rich merchants and their families?
As an artist, I feel that there is a sort of scale of priorities. Making money with my art skills is more fun than making money with any other way. But there are things I like to draw, and I'd rather make money drawing those instead of things I don't like to draw. And I'd generally rather make money by drawing whatever the heck my muse directs me to draw, instead of what I think is likely to sell, or what someone with a lot of money would like me to draw.
Different people have different priorities, someone who's willing to draw whatever the hell comes their way probably makes more money than I do, and that's their choice. I have an artist friend who mostly dropped off the net for a few years because he was doing lots of very specific fetish art for a rich client who didn't want it posted anywhere, and was willing to pay handsomely for that. He was willing to do that, I wouldn't. He also had a kid to support, I don't.
And... poor Vince certainly could have used a richer set of patrons, yeah. He could have used a lot of things. Possibly including some modern psychoactive chemicals. Dude was pretty fucked up.