People who suggest this fail to understand that to a google-brained PM it would be a complete and utter career-destroying faux pas to suggest that they should make a non-web app, even for a purpose as trivial as a firmware upgrade.
Doing it via the browser means they get support for Linux out-of-the-box. If this was a long-term thing, they wouldn’t need to care about things like Apple switching architectures for the umpteenth time.