BaronHK
I don't see any real difference with Fennec F-Droid and Blink browsers, except that Fennec supports ublock-origin and on some sites 30-40% of the resources they want to load are ads and tracking garbage, bitcoin miners, fingerprinters, chumbuckets, etc.

So I might be biased because when a site is nearly half crap you don't want and you don't load it, that browser will be faster than something like Chrome, which is designed to stop you from blocking anything nasty.

Firefox Preview seems to support Tracking Block which ultimately whacks most of the ads, since most ads track you, but Mozilla seems to have removed extension support. That's the main thing that makes their mobile browser worth something to me, so I may just switch to Samsung Internet with an ad blocker if this remains so.