QBs get overdrafted because of their importance in the game and potential value if you hit on one.

Draft success in the aggregate is basically a coin flip, having more/higher picks increases your odds slightly.

I'd also say that the team a player lands on matters a lot.
- If they have a garbage organization and coaching staff, they aren't going to develop. (Justin Fields)
- If they get shoved on the field as a Day 1 starter before they are ready with a leaky OL, they are going to fail. (Zach Wilson)
- If you trade away your best WR, they will struggle. (Bryce Young)

Granted, those QB examples were unlikely to beat the odds because of other shortcomings, but the situation they entered certainly did them no favors.

Jordan Love had time to develop with a patient organization, had a halfway decent OL, and while the receivers were a wildcard, by end of year they had gelled. The big assumption was he'd have a good running game with Jones/Dillon and the defense would hold up, but by midseason things started to trend up.

FWIW I think not having a single, psycho owner helps GB a lot -- the fans and the owner often want the shiny new QB to play right away when they are still learning the playbook. Meanwhile the coach and GM are trying to keep their job. There have been a lot of good QB prospects ruined by being drafted into bad environments.