I agree with you on your assessment of the NCAA and the need for a better solution for oversight and governance.
However when you say “run out players they do not want”, what actually happens is the new head coach meets face-to-face with the player and has a brutally honest conversation. The player is informed they will be demoted to third string so the new transfers/recruits get playing and practice time. The player is then left with an adult decision to make. Stay, keep the scholarship and graduate, but never see the field. Or transfer out to a school that does want them, on scholarship, and maximize their remaining player eligibility. It’s not pretty but a coach is not breaking any rules by telling a player they won’t see the field on their team. In fact it’s their job to set the depth chart.
This is what happened to my friend’s son who currently plays in the SEC. Both were initially shocked by the brutal honesty but also appreciated it after the sting wore off. They know where they stand and can adjust accordingly.