Between the Material You design and move to break apart the Chrome browser from ChromeOS, now more than ever, ChromeOS is Linux with Google's desktop environment.
There are 2 ways to do it, either via depthboot(software only, no custom firmware, lots of manual OS prep, 0 risk) or custom firmware(maybe physical, model dependant, no os prep, small risk). For custom firmware you usually have to either bridge an internal jumper, unplug the battery, or build a custom cable, depending on your model.
While it is allowed it's not supported by google.
I would never recommend buying a Chromebook with the intention of replacing the OS unless you're looking for a project or you're getting it for cheap.
Do you have to jailbreak the hardware to install another OS or is it supported?
There are 2 ways to do it, either via depthboot(software only, no custom firmware, lots of manual OS prep, 0 risk) or custom firmware(maybe physical, model dependant, no os prep, small risk). For custom firmware you usually have to either bridge an internal jumper, unplug the battery, or build a custom cable, depending on your model.
While it is allowed it's not supported by google.
I would never recommend buying a Chromebook with the intention of replacing the OS unless you're looking for a project or you're getting it for cheap.
TLDR it's harder to replace the OS on a Chromebook than a Mac, and you get none of the benefits of Mac hardware.