Enrollments are locked in, but there are two different ways to delegate. With delegation, it's not locked in but can be withdrawn at any time.
Delegation does not directly benefit specific people the way an enrollment does, of course.
So when I talk about targeting supply, it's the delegation options- because you're right, normal enrollments and sponsoring (the way we market and the way most think of SBI) is never going to be perceived as a good alternative to delegating to a bid bot.