I think that is another effect of NIL. If you are the starting QB -- you are going to be getting many more offers as the face of a big time college program. If they are sitting behind someone for a year or two -- that is going to cost them money.
Most of these top QB recruits -- they are only looking to stay in college 3 years and then go to the NFL, so if you sit a year or two, it is going to cost you some money.
Granted -- they will still make money as a backup, but nowhere near what they'd get as a starter.