You are at the sole mercy of your direct supervisor. If God forbid they don’t act professionally, or do not like you, or have something against you, they will ruin your career with impunity. You will have no recourse as if you go to their boss they will simply say they rely on your manager to determine your level. This is the only real con, though it’s a big one.
There has been an exodus of great employees this year, though disillusioned, they’ve been made better for their time at OneMain, therefore land at better paying positions elsewhere.