As I've opined on many occasions, the "adults" in the room should do a much better job finding ways to accommodate EACH kid's best interests.
That said ...
One point buried fairly late in the piece is the congested high school schedule and its impact on training. If you look at SCHSL, some programs are packing as many as 26 "regular-season" matches, five playoff games and 2 full-dress scrimmages (33 events) into approximately 110 days. Eliminate most Sundays from the training equation, and consider that many coaches train "light" the day before a match, and what's left?
In short, not enough days to develop the fitness, technical competence and tactical awareness needed to maximize player development.
When a kid ends the high school season tangibly less fit, MATCH FIT, and technically sharp than when he started, there's a problem.