Any browser will need a decent internet connection, but over all the brave browser is snappy for me, and much better configure wise to stop adverts loading, go into settings and stop the adverts that will offer some more speed even on a poor internet connection.
Regular Firefox user here, but as a sometimes alternate, I use Vivaldi. Based on Chromium (so the same Chrome / Edge etc add-ons work), more features than I need (like email client and calendar - but they can be turned off), seems plenty speedy and has no 'safe' ads, as with Brave - or tracking as with Chrome.
I just tried to use Brave. There's so many gimmicky things in there it just seems shady; crypto stuff, earning rewards, etc it all felt so unnecessary. The built-in ad blocker was neat and maybe it's just Chromium based browsers but there are far too many options and sub menus it's exhausting to go through them all.