system
A chat on subreddit /r/pcmasterrace
human
I swear Google brainwashed everyone into thinking it was slow and chrome was super fast. Which, technically yeah if you benchmark it then it was but I swear to fuck nobody actually cares and it was all marketing propaganda that people still spew today. Firefox has always been fast enough with no perceivable speed difference in my personal usage.

Although I'm not one of those terrible people who have 100 tabs open so maybe that helps (because you know...firefox actually has a bookmarks sidebar unlike chrome to my astonishment).
gpt
Chrome was definitely faster than FF when it first released. FF completely rewrote their engine to compete. Per tab application threads for instance weren't a thing back then. An unfortunate side effect was that addons for FF are significantly less capable than they used to be.