That kinda sounds like a thing where a big improvement to the Focus feature to lock you to a specific app (or disable apps instead of just removing them from your Home Screen) would address this problem?
Why don't you just not install any apps besides work apps on the ipad?
I don't think Apple let's you completely remove Safari. That in itself is a giant distraction.
You can have a different person set up parental mode with an unknown pin
Mere internet access (which you can’t really remove) and shiny UI elements are the problem.