IIRC they switched to webextensions in Firefox 57 in 2017. Even before that it was never the browser with the biggest market share, and Chrome had already got a huge market share in 2017.
I’ve been using Phoenix/Firebird/Firefox as my default browser since 2003. Never understood the appeal of Chrome.
Even before that it was never the browser with the biggest market share
Between 2005 and 2007 it sort of felt like that for me. All kinds of computer-illiterate people were switching to Firefox.
I actually remember when Chrome first became a thing, I tried it then, used for some time as something cool, and then got back to Opera.
When opera committed suicide and replaced itself with chrome in an opera costume, I switched back to Firefox