It's semantics, but I think it's useful to reserve the name "Linux" for devices that are the unrestricted version of the OS, otherwise the name starts to become as generic as the term "smart".
1. Yes, ChromeOS is based on Linux, but it's not really what most people would refer to as "Linux". I think this is what you're talking about.
2. ChromeOS does have, however, some great technology to run an unrestricted version of Linux in a container, called Crostini: https://chromeos.dev/en/linux . I used to use a high end Pixel book (which was a great machine, really sad Google discontinued it - surprise, surprise, I know) as a primary dev laptop, it ran VSCode, postgres, etc. very well.
Disclaimer: I daily utilize a cheap Chromebook as a lightweight typewriter, and I love it.
However, it's important to note that Linux on this device is subject to certain restrictions:
It operates within a containerized environment, which limits both disk space allocation and system-wide access. Accessing the terminal requires navigating through a "virtual machine", and files are shared within the /mnt/chromeos directory. Additionally, the utilization of USB devices is layered behind the primary operating system support and Linux backups are separate from the overall operating system backups.
Something interesting about Crostini is that it uses 9p to bridge filesystems, just like WSL2. It seems that 9p has "cracked the code" on bridging filesystems over virtual machines and differing operating systems in a way that other options never seemed to do quite as seamlessly, which I find rather interesting. Maybe it's because it comes with less baggage than CIFS? Easier to extend? Less complex than NFSv4? I'd love some commentary on this.
The filesystem bridging between Crostini, the rest of ChromeOS, and Google Drive is brilliant. It also transparently integrates SSHFS into the filesystem and the file browser.
Well, for starters, with dm-verity and secure boot to prevent modifications to the root filesystem.
IMO it's beside the point. Calling ChromeOS "Linux" is like calling cells "mitochondria". One could argue that the same could be said about the somewhat standard Linux desktop stack you'd find on Ubuntu or Fedora installs, and that's true. However, that's probably mostly just a consequence of the fact that Linux doesn't have an actual standard userspace. The closest it has is the defacto set of components you're likely to find in any GNU/Linux distro, and they are quite different than what you'll find when you boot up ChromeOS or Android.
