This discussion is about the permissions that applications get. Desktop Linuxes don't have such an permission system in place - "just run as root" with ultimate trust in the application is quite common. Sandboxing isn't a thing either.
Amount of Chromebooks on sale across European electronic consumer stores, less than 1%.
The 1% is left for when they occasionally pop up under "deal of the day", when the shop decides to test waters and is more than happy when it finally goes away after a couple of weeks on display.
GNU/Linux security is better than ChromeOS because the updates are guaranteed for longer than six years, if one buys a laptop from someone like System76, or plenty of small Linux shops, it can be properly configured with encryption, LinuxSE, Flatpak/Snap/whatever.
Windows is a proper OS and its cloud offerings are not new.
Security must be the default. Automatic updates, sane default configuration. And a user interface that supports security.