I honestly don't get people that say "I use Chrome because I'm used to it". It's not like Firefox and Chrome are immensely different when it comes to UX, right? The interface is pretty similar.
Sure. But I also professionally use a product that works better on Chrome (and Edge nowadays) so I'm lazy about it. Eventually I'll move to Firefox on my home PC. But in on my work PC and phone 95% of the time already so it's not going to make a huge dent.