The headline is true. ChromeOS is Linux with Google’s desktop environment. But it obfuscates the details. It's a damned by omission statement. It has some really good sauce to help you not notice often, but it's not at all a Linux desktop environment one can regularly use. You can do a lot of Linux desktop-y things but only through well crafted special unique wrapped processes that mostly but not fully help mock & emulate a regular Linux desktop. Even though it now runs Wayland, the apps you want to run will have atypical intermediates up the wazoo.
And no one else uses any of this tech. ChromiumOs has so much interesting container tech, does such an interesting job making containers think they have a regular Linux / FreeDesktop environment. It's far far far far deeper virtualization than for example https://github.com/containers/toolbox . But you know what? Google has made zero effort to get these pieces adopted elsewhere. It's open source but not intended for use outside Chromium/ChromeOS. I respect & think ChromeOS is a quite viable Linux, and it's so much closer to the metal & more interesting, amazing tech, but my gods Microsoft has gone 300x further to establish wsl2 as a sustainable community effort folks could use & target, in a way that ChromiumOS has done nothing about.
It's sad how Google has transformed from a company that appreciated & worked with ecosystems, that drove things collectively forward, into an individual player that does their own things & delivers from on high. ChromiumOS is such an incredible effort, but it's so internernally drive & focused, and it's hard to believe in such a wildcat effort, even though it's so so good. It keeps coming into better alignment with Linux Desktop actual, but via shims and emulations that no one else cares about or which seems marketed elsewhere. And that inward focus makes the whole effort both so exceptional & promising, but suspect. Such a different nearby but alternative & separately governed universe. ChromiumOS/ChromeOS do excellent at faking being a Linux desktop, and wonderfully have increasingly drawn more strength from that universe, but are still wholly their own very distinct very separate very controller other space. In many ways that's great, secure, good, and miraculously transparently done. But it's still hard to really trust, being such a weird alien impostor, faking so much for end user apps, and there's tension in believing ChromeOS will keep straddling the rift in pro-user manifestations forever.