Well ChromeOS is basically a monolithic browser based OS. These will likely have apps deployed which contain one copy of Chrome each. By the time you get three vendors' worth of stuff on it then you're running three isolated browser stacks and eating up RAM. I'm sitting here on a Mac with Teams, Outlook and Slack open and there's 18 gig of RAM gone for example.

As for Chromebooks, they are fucking awful for education. The abject disaster that is Google Classroom needs to just go away. NOTHING works properly, has any inkling of any reasonable design or engineering or is intuitive. I've seen so many students struggling with them.