Yep I use Firefox for everything, but I keep chrome installed as a backup when needed.

The most common reason for opening chrome is for Google related things. Certain google docs features like the add-ons store only worked in Chrome, but the add-ons themselves work anywhere. Or signing into Google Drive desktop app failed when the auth window opened in Firefox or Edge, but it worked in Chrome.

I just thought that was Chrome breaking things in other browsers intentionally, since no other services had that kind of issue.