A school cannot function without a behavior policy that involves sanctions; detentions, isolations, etc are necessary no matter what ideologues think of them.

The proof is in the dire consequences schools face when they remove them:

Have a listen.

https://open.spotify.com/episode/608OiRmcYfUdSw0ud0GMi2?si=7xSIJiibT8qTooNGPrym2g