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.
I would definitely get a Chromebook, but only once you can change the default browser from Chrome without needing to do any weird workarounds like Android apps
As someone who has owned a Chromebook for several years, I can tell you that you shouldn't. Hardware wise it's hard to beat Chromebooks at their price points, but the complete lack of control over the system is a deal breaker. I don't have time to list all of the issues I've had. In many cases what would have been trivial fixes on a normal Linux system required full reinstalls on chromeOS. Like the time I accidentally filled up the fairly modest system storage. The system refused to allow me to delete anything, requiring a reset just to get local file management abilities back.
I ultimately ended up installing full Linux on it, which ended up being a whole other ordeal due to all of Google's "security" features.
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.