In BB we get all players with the skill level really of benchwarmer or less and at 18~19 with some having potential and others not. This is not realistic
But it makes BuzzerBeater interesting and playable. In NBA we have 30 teams, in BuzzerBeater we have 50k. It is impossible that game with 50k teams can work in the same way as game with 30 teams. So comparision to NBA is wrong. NBA is closed league without promotion and relegation. So what? First 30 users joined to BB should play in NBA and other shouldn't have even chance?
In real life the best player in 2000th the best club in country is even worse than 18yo rookie in BB ;-)
Do we really want realistic game? So every club should hire hundreds workers - lawyers, accountants, bodyguards, etc, etc, not one manager for few minutes per day.
In NBA we have ~450 players, in BB we have ~800-900k (in alive clubs, if bots included I think we have ~6-8M). So scale of skills must be wider. I wrote it in other topic, if we want to use BB scale to describe NBA players, then the worst player in NBA has skill = 17-18.
Good online game must be unrealistic in many aspects.