I actually have seen this in my current company. Many developers switched browsers away from Firefox. Some even switched to Edge since it plays better with the battery. I know early adopters of Brave from its early years too.

When things get a bit bigger in JIRA, Firefox's JS engine struggles with horrifying amount of JS JIRA throws at it. Same for Google Meet and Zoom.

I tried and realized Firefox has a huge power consumption penalty on my Android phones and a considerable one on my laptop. I still keep it as a secondary but it is still not there yet.

IT people in my both current and previous company prefer deploying Google Chrome. Previous one was a complete Microsoft shop, they didn't use the built-in Edge but removed it and deployed Chrome. There is quite a bit Microsoft sysadmin know-how about Chrome, less for Edge and even less so for Firefox.

If you're privacy-conscious you'd have searched or visited blogs like this[1] or privacyguides.org or privacytools.io. They all point out issues.

They are all a factor. Many people still install Chrome because the apps / websites they visit tell them so. If you used web-based engineering software, they will always recommend Chrome.

Google Docs of course works better on Chrome, intentionally or unintentionally Google will roll out more optimizations for it.

[1] https://madaidans-insecurities.github.io/firefox-chromium.ht...

Sorry, I should have made it clear: my comment is about the general population. It is about why Firefox is losing market share. Not about IT people, privacy-conscious people or alike. It is about why the average Joe stopped isn't using Firefox.