As currently positioned, USC will be considered like the Dallas Cowboys... perennial underachievers.
If you can't do it with Caleb Williams, I am not sure they will ever get back to the top with Riley. Riley will have talent, but is not the coach to help a good team become great, or an average team to become good. I think we will see that over the last few games of this season. In the end, I think Lincoln Riley's USC tenure will be thought of as "what could have been."
I hope USC is just bad enough to retain Lincoln Riley.