Despite my constant advocacy for Firefox for over a decade, a family member whom I respect greatly told me directly and in no uncertain terms that they do not wish to use Firefox and wish to switch to Chrome instead because of numerous issues they have observed. And the worst part is that as much as I wanted it to, Firefox wasn't up to it. I cannot help but think that this is a microcosm of what's happening more broadly.
You know, that's the real question we should make before going on this entire exercise. Are the usage statistics any reliable?
Firefox is the one browser that blocks the things those sites use to measure market share. Why would we expect their results to be real?