Netflix has introduced Profiles for their service and it's helpful (not great, but helpful). Why can't you do this with IOS?
Please create the ability to make profiles for other people who use a single device (like an iPad) and allow limitations for already installed apps "Dad profile gets these apps and can use it at these times and the kid only sees these apps during these times" -- Use faceID or fingerprint (or code) to access those profiles like you would without them.
This would be such a huge help when my kid steals my iPad. This cannot be that hard to do.