My take on FF "decline" is that FF user share (%) dropped because the pie started expanding (especially on mobile). New internet users are likely to be Safari or Chrome users for whom the browser they have is good enough. And Firefox on mobile is simply not as fast as alternatives (the bar set by Chromium Android is very high), kinda painful to use unless you have a highend device, esp. JS heavy sites like Twitter work much better on Chromium.

This doesn't fully describe situation, but over last 3 years, mobile users went from 50% to 75% users in my prev company's data. And Firefox is nowhere in those mobile stats.

Number of Firefox users is dropping, not just Firefox market share.

Firefox has less users than desktop Safari. It shouldn't be that way, but it is. When you factor in mobile it gets worse because Chrome (the Android default) and Safari (the only real choice on iOS) are so dominant.

Also, the market share numbers reported by client side trackers like StatsCounter are very close to log file collection and analysis by companies like Kinsta.

iOS Firefox is actually quite nice, I've been using it as my default for a year now. Biggest win for me is tab sync, so it's pretty easy to open a tab I had loaded on my phone in my desktop browser.

Sure, it's using Safari as a renderer, but these days that's hardly where the differentiating value is.

How are you so sure? You really didn’t address OP’s point about content blocking and privacy tools.

Content blocking does not change requests to the originating server. Firefox would have much better market share in log file analysis method studies than it does in client side tracker based studies if the OP was correct.

> FF's privacy focus caused

Even before the whole privacy focused thing FF was already in decline to sub 10% market on Desktop.

If you think about it the other way around, it is still hanging on to 5-10% of Desktop market after all is actually quite good. At its peak, Firefox was closing to 40% in some European countries. If you consider IE in Business Cooperate usage and Firefox are not available in those settings, 40% is a really big deal.

Do you trust Mozilla? They share the numbers.

https://data.firefox.com/dashboard/user-activity

I’ve watched the decline for years, straight from the source. These usage numbers are not affected by privacy settings.

Firefox users avoiding those tracking sites would result in an always low user share, it would not really explain the user share dropping. Maybe an increase in privacy minded users could explain a percent or two, but not most of the drop.

Unfortunately that's not a likely explanation. If you do even the simplest possible measurement, which is just recording user agent strings and IPs, you won't end up undercounting Firefox clients

Either uBlock Origin or Matrix comes with user agent spoofing, it's not like the practice is that rare.

Matrix used to do this but doesn't anymore [1] and uBlock never had that feature. Please don't make stuff up.

[1] https://github.com/gorhill/uMatrix/issues/927

I don't think it's fair to call not knowing that a feature was removed from a discontinued app "making stuff up."

I was clearly wrong, though it is easy to change your user agent it's unlikely that many Firefox users have done it.

You're right, I misunderstood your comment. I interpreted what you said as in, you can get this feature via either Matrix or uBlock. I see now you meant one of those has the feature and you weren't sure which one had it. Sorry about that. In my defense I think it can be read both ways.

I'd add there is a large gap in usage between uBlock and Matrix. uBlock has over 10 million users whereas Matrix is somewhere over 100,000.

Does uBlock Origin turn that on by default? That's the only way I could imagine such stats being wrong by a wide margin.

By mozilla's own metrics only 30% of their users use any addon at all.