As a student? In middle school, yes, High School, no. What I remember was that we got four bathroom passes for the quarter with our names on them, color coded by quarter, to ensure no one abused the system. The idea was so that you only went when you truly had to go rather than as a way to get out of class.

As a teacher, people who don't work in schools vastly underestimate how many middle and high school students go to the restroom to vape, chitchat, sell or buy drugs, put on makeup, play or text on their phone, talk to friends, wander the school, and so on; some students will "go to the restroom" to do just about anything other than actually use the restroom. It's not necessarily equally bad at every school, but it has been a problem at every school I have worked in. Even back when I was a High School student at a place decently regarded for its academics, we had a bathroom more known as the home of the stoners than as a place people did number 1 and number 2. At my current school, I can see the entrance to the Men's room from my classroom, and you'd be surprised at how many times I can see someone go into the bathroom during passing period and then ask me to go again, five minutes later, once class has started. Before we got an electronic sign-out system, it was very easy for kids to abuse the system, and even with restroom passes written into agenda books, people would just grab their friend's agenda books once they were past the daily pass limit, or they'd lose them (or "lose them" as the case may be) and have a teacher write them a pass, with the teacher not knowing whether they had tried the same tactic every period of the day or not. Even now, it's not perfect, and the official bathroom passes we've been issued have been known to disappear, some genuinely lost but many opportunistically snatched.

The reason schools have bathroom policies like this is that, surprise, some kids abuse the heck out of the system if left to their own devices. Thus, most schools have a limitation on daily (usually) bathroom passes. Of course, kids that have a legitimate medical need to use the restroom frequently are exempt from those limitations, and as a teacher it's typically pretty obvious if it's a legitimate bathroom emergency and exceptions should be made. But a few bad apples can very much affect these policies for everyone, as with anything else.