If anyone is a Dwarf Fortress fan, you guys might have seen a guy called Kruggsmash around. He basically draws what is happening to his Dwarves in the game, since its main text and random symbols.
I remember watching his videos waaaay before he started to draw, when it was just him editing his videos and telling a story as he played. Very fun to watch. He didn't have much of a following at the time (if you see how Dwarf Fortress looks, you can understand the niche fan base it has), but he kept doing his thing.
Later he started to add little doodles of what has happened, his fort, the Dwarves and monsters that interacted with it and so on. Just something to add a little more interest into his videos that he enjoyed doing. This later became very popular, and he started focusing on doing more drawings for his game, as well as upping his story telling.
A year or two later, he is making something like $4,000 dollars a month on Patreon. It has dropped to $3,000 now days, but that is the fickle beast that is Patreon. But from a guy who had zero intention of making it big (as in wasn't begging for subscriptions or spamming us with ads), he has done amazingly well for himself.
The moral of this story? This guy played a game that he loved, and drew things for his own enjoyment. He kept to a schedule, but didn't treat it as a job or came into making these videos with the goal of making money off it.
But because it is niche community and literally no one days a Dwarf Fortress Let's Play better then him, he got popular. He didn't chase the money or a career, he saw the opportunity and took it when presented.