Extensions were a major selling point, even though as you say, most regular people didn't use them. But the advocates were almost all power users. Mozilla co-op

Extensions were a major selling point, even though as you say, most regular people didn't use them. But the advocates were almost all power users. Mozilla co-opted power users by making a browser that power users wanted and convincing them to evangelize it to regular people. Through various decisions over the years, but especially the extensions, Mozilla totally nuked the power user case - they decided they wanted to make a browser for the average grandma, not power users. So their core group of supporters lost enthusiasm as they removed feature after feature, and grandma isn't going out and downloading her own web browser, unless... ...it's pushed by a multibillion dollar megacorporation that pushed it relentlessly on all the biggest web properties (Google and YouTube), TV commercials, and had it packaged in installers for other software. That's why Firefox lost: there was no possible way it could complete with Google's marketing of Chrome, while at the same time it alienated its core of supporters with very poor leadership decisions that fundamentally failed to recognize who its constituency was. I never noticed Chrome itself being noticeably better than Firefox - I'm sure it was in some ways, but it was definitely never the kind of difference we had between IE6 and Firefox. I remember this NYT ad very well. It was an incredible moment of positive energy. It's really sad Mozilla blew it, and to this day their leadership doesn't seem to recognize what went wrong.