I did not observe that the quality rises with the level of the facility as well. So maybe that could be fixed in the description.

Why one should upgrade nonetheless: Upgrading the youth facility reduces the time you have to wait to get youth players. The low quality one (1* or 2*) brings you regularly some fresh money. You invest once (for each update), but you profit from that time on. The expensive is normally only a good investment for power trainers. If you don't plan to do that, invest your tokens elsewhere.