Look at the roster breakdown from LWS's post.
Seniors: 30
Juniors: 9
Sophomores: 11
Freshmen: 33
Heupel was facing a really unique roster issue this season with over half of the roster being underclassmen and the largest group being Freshmen (redshirt and true) and second largest being a ton of Seniors. If you want a roster that can survive the season, you better keep a lot of those Seniors happy so they don't leave.
Let's be honest, most of those Seniors are mid to lower level SEC talent. Heupel has been handcuffed in some way with this roster every season. Next season will finally see the balance of the roster shift to something a little closer to normal and the 2025 season will probably be his first where he shouldn't have any notable roster issues to manage.