You can even install linux on Chromebooks, and ChromeOS has upstreamed / opensource many of their codes.
In other perspective, ChromeOS supports running Linux apps w/ GUI without much differences. You just open your terminal, type `apt install XXX`, then `XXX` should work out-of-the box.
I don't see any reasons that ChromeOS is less open then macOS
Any? Crostini is neat and all, but it's a VM running inside of ChromeOS, so it's restricted in what it can do.
The entire system firmware is open source, so it’s relatively straightforward to replace the system firmware with Coreboot and EDKII to boot normal UEFI Linux. It works excellent. mrchromebox.tech and docs.chrultrabook.com have all the nitty gritty details.