Depends upon the sport. My kids played soccer, so I can speak to that. The barrier to entry is minimal. When they played Classic League, most of the teams were lower income, Hispanic kids and we've moved up with many of the same families we started with. Most clubs subsidize dues if needed, but it's the travel that gets you. Many families carpool, share rooms, etc to mitigate the costs.
Sports also suffers from the same issue kids are having with phones/social media - they have it because everyone else has it. If your kids are good at their sport, along with their peers, they all join competitive leagues and the level of competition is commensurate. It only gets tougher the higher you go.
Then again, you have many HS players that are damn good players that don't play club ball and are fine with that. The difference are touches/time and the quality of the coaches. Keep in mind also that MANY kids peel away as the leagues get more and more competitive.