If you don't care about Verified Boot, you can install ChromeOS-Flex on a Framework Linux device (https://www.reddit.com/r/framework/comments/um0mk6/chromeos_...)
On the other hand, installing Linux on Chromebook hardware is straightforward.
The options are:
1. Use the Debian Linux VM (Crostini) that is already present on Chromebooks:
All you do is click on a few buttons in the settings. This approach preserves Verified Boot.
If you want to replace ChromeOS on a Chromebook with a Linux distro, you can use Crouton: https://github.com/dnschneid/crouton
This approach removes verified boot.
1. https://www.chromium.org/chromium-os/chromiumos-design-docs/...
Crouton? It won't have full capabilities being in a chroot, but I remember it being more than adequate for almost everything I needed it for. 5 years ago.
https://edu.google.com/chromebooks/chromebook-repairability
Some school districts have summer internship programs for students interested in learning how to do the repairs.
https://www.pcmag.com/news/google-encourages-kids-to-repair-...
But after a few years you can no longer update your web browser.