This is a great point, and it's also why guys who are similar athletic profile to Messi are going to be the best path to how USA finds a "star." That's why Cavan Sullivan (5'7") is the best player in the USA youth pipeline while guys with a profile similar to Mbappe aren't even playing soccer in the USA. I was shocked to learn that Mbappe is actually slow AF relative to hundreds of guys in CFB ... his top speed translates to like a 11.0 or 10.9 100 meter. He's like a tiny bit faster than Drue Tranquill was in high school, for a Notre Dame linebacker comp, yet he has "world class" athleticism for soccer.
There is some truth that #1 thing killing USA finding "generational" players is that all of the 5'9" to 6' tall "good" athletes are routed to football. College football has many full scholarships + NLI money + potential NFL money *and* it is the cultural #1 *and* it doesn't require near the investment in skill that soccer does. It's a funnel. It's not about the "LeBron" type guys, it's about how you have dudes playing corner for Purdue or Boise State that have better athleticism to Mbappe and we have no idea what they could be at soccer. All of these guys in Europe go into academies at an early age, and then they find the 1% that actually have world class soccer skill to be on their national team. PLUS they add the Messi / Iniesta / Cavan Sullivan types. USA is missing the funnel.
So really, we're talking chicken and egg. You're taking about 500+ or a 1000+ kids a year that have Mbappe level athleticism and 0% of them are focusing on soccer. The odds are 1% of that 1000+ might have a lot of soccer potential and we'll never find out.
And by the way, see this across basically all sports. I had a really good lacrosse player drop the sport for football ... he'd never played football in his life ... and get a D1 full ride after two seasons of doing the sport. Football requires ZERO skill and if you have the right athletic profile there are SO MANY OPPORTUNITIES relative to every sport in America. The reason basketball still continues to be successful is that the "elite" pyramid is smaller and those body types don't actually overlap much at all with football. Baseball, soccer, etc. all lose most of their potential top tier athletes to football starting in HS.