[theamk]

Sounds like you don't want a Linux system, but rather a Chromebook. Have you seen https://chromeos.google/products/chromeos-flex/ ? Install it on your computer and you get Android-like security model, including only verified software and lack of "sudo" or any sort of root access.

[charcircuit]

A Chromebook is a Linux system. My concern is with Ubuntu improving their security posture. Telling Canonical to give up on Ubuntu and switch everyone over to ChromeOS is not something that I predict would work.