Right, but the underlying engine doesn’t matter much practically speaking. I don’t think I’ve ever run into a situation where the browser on iOS limited me from doing things I would want to do on mobile.
I use FireFox on iOS because it syncs with FireFox on my laptop.
I disagree, plenty of posts here that start with "doesn't work on my iPhone".
Apple forces you to adjust to their terrible browser engine by taking away your users' ability to install another browser. Many websites put in the effort to make their stuff work on Apple devices but that's far from a given.