Not mentioned is the password situation. That is the bigger lock-in than bookmarks. I don't know what is the tech stack underneath or even what chromium does. But as a normal-ish chrome user I know behind the scenes google is managing my passwords and it would be a nightmare to switch. Too many sites I wouldn't know how to access without their password management. That is true lock-in.
This file can be imported into Firefox with https://github.com/louisabraham/ffpass/ (Firefox doesn't support importing the passwords from a chrome profile on Linux). It shouldn't be too hard to import it into your password manager of choice, either.