I'm a middle school teacher and generally very permissive with my students when it comes to using the bathroom. That being said, bathroom breaks must be managed. Students routinely go into the the bathrooms to fight, smoke weed, vape, have sex, and other nefarious activities. In a perfect world I would love for my students to be able to get up and go when it was necessary, however, as a teacher I have to keep tabs on whose in and out of my classroom.