[Sylos]

W3Schools isn't a terribly reliable source for market share, since they only measure their visitors, which is primarily webdevs. And Mozilla offers a competing service, MDN, so webdevs primarily using Firefox probably also have a preference for MDN.

Besides that, they don't separate between desktop and mobile. Marketshare on mobile hardly reflects user opinions, if this is what you were trying to imply.

Other sources, like NetMarketshare, show rising numbers on the desktop.

[Vinnl]

While this is true, it is unfortunately hard to deny that Firefox has been losing a lot of market share, and that the situation on mobile is especially bleak.

That said, keeping things the same would obviously only sustain that trend. Hopefully Firefox 57 and above will help them reverse it. I'm hopeful though, if it doesn't, I don't think there's much else they could've done.