I don't think it is. Chrome these days feels like it's being maintained solely as a platform for running Google Docs. And Edge is based on Chromium, a good indication that Microsoft is not very interested in aggressively engaging in browser wars.

So I believe that Firefox has a good chance to gain ground. And Firefox is already doing great and feels much fresher, at least from Chrome. More importantly, we are a far-cry from the crippling incompatibilities of previous browser wars, which essentially required you to replicate the bugs of your opponents.

Also, a "win" for Firefox wouldn't necessarily be toppling Chrome from #1. E.g. a healthy market share percentage + being the top self-installed browser would be a win. Dominating the browser market may even hurt Mozilla Corp., as it could force an aggressive reaction from Google (reduced funding, or even buying them if they can get around anti-monopoly regulations).