A Reddit thread by u/nixcraft (via itsfoss) noticed a downward trend from Firefox's own Public Data Report that shows nearly 46 million users ditching Firefox over the last three years for a different internet browser.
At the end of 2018, the reported active monthly users of the Firefox desktop client were about 244 million, but in Q2 2021 that number dropped to 198 million users. While still an impressive number, the slow decline of users could be a more telling sign of things to come for the top alternative to Chromium browsers.
Mozilla launched Firefox back in 2002 as a more user-friendly web browser that focused on privacy and security. By 2008 Firefox was responsible for 30% of all browser usage, with Internet Explorer still having the lion's share of the market at around 60% and Google Chrome in its infancy. Now, Chrome sits atop the web browser throne at 65% of the market share, with Firefox and Edge accounting for around 3% apiece on desktop, mobile devices, and consoles.
Why the drop-off? Firefox users have often complained about the lack of substantial performance updates in the last few years, along with the divisive Firefox 89 UI overhaul that convinced some long-time users to try their luck with other browsers. It also doesn't help that Google Chrome is now the default browser on nearly all Android devices around the world, Microsoft Edge is doing the same on Windows machines, and we can't forget Safari on Macs and iPhones.
With more and more websites optimizing for Chrome so that they will load faster, it'll be an uphill battle for Firefox to remain competitive and peel users away from the Google ecosystem. With 197 million users, Firefox isn't going to disappear overnight, and some folks still really like what Mozilla is doing. Still, it'll be very interesting to see what the next steps are for the open-source browser.