I have to use either edge or chrome for work, so keeping a consistent ecosystem for home too works well. I can’t recall why FF couldn’t be used. Windows Hello, maybe? Anyways, when I checked 3 or so years ago, it was a conscious decision on FF’s part to not support an absolutely critical feature. Not having Adblock would be enough reason for me to want to juggle two browsers, but FF is simply not a desirable option right now, as much as I would love for it to be.

Or at least change their user agent to skew the statistics. :/

Statistics come from google analytics, which most Firefox users block. When I compare stats from my webservers with GA, it’s clear that either bots overwhelmingly prefer Firefox UAs, or it’s underrepresented in GA stats.

If the Firefox version is more than a year old, it’s a bot.

Or, the first time I've booted this computer in >1 yr.

I’d really discourage browsing random websites with a browser that is years out of date.