Thing is though that since Chromium is open sourced, there's not really a downside to using it as a base since it effectually sets the standards now, unlike the 90s when proprietary IE set them. If Mozilla swapped Firefox it it they could sack the morons who continually make the UI worse, focus on security, privacy, speed, and efficiency, and make the mobile version a true competitor.
They and volunteers, or maybe a merge with Canonical, could keep a non-Chromium Firefox version up as a fork for use on Linux (though Chromium works better, at least on Linux Mint on VBox) and for privacy minded Windows users, as an alternative. where speed and absolute efficiency are not the priority.