Crostini is still an esoteric dev only feature. No user is going to use it, or even be aware. When they need to run any apps or work with files, they don't have any options.

Why can't ChromeOS be a standard Linux distro which runs apps in a flatpak (and validated by Google). That way you can't screw up your machine, you don't really lose any perf, and you have the best of both worlds.