Because it will quite quickly become apparent that there’s no path to first-team football.
Disagree with quite a lot of what goes on at youth level, actually. City are only a byproduct of a rotten system, but they’re taking it to the next level. There needs to be a much fairer compensation system (EPPP’s a farce), stricter limits on scouting, compulsory relationships between regional clubs at different levels, and limits on the amount of players per age group.