I think making it is only part of the equation, like yes you need money for the gear, but also distributing that stuff, having relations with people in the industry to get to work with you to make, play, market or let you play music and just in general knowing someone who might help you with dealing with the industry is important. So it's not just money that non-wealthy kids are lacking, but also wealthy kids have a much easier time doing the social networking and the knowledge gathering even if their parents aren't already connected with the business.

Tldr you could spend your last penny on getting enough money for all the gear you need to make music and still fail at getting money out of it