More will follow, especially if Mozilla continues to develop Firefox against the interests of users, much of the majority distros already include Vivaldi as an alternative in the repositories. You look at it as like, Vivaldi is the best alternative to Firefox, in view of the others on the network.

Brave? well, is a good browser, but for it’s incoming it has a reward system, that is, it stops blocking trackers of its sponsors, including Facebook.

Opera? the worst of all, Chinese companies and privacy is a oximoron.

Some fork of Firefox? alll the conect to Mozilla, apart most are outdated or not very stable.

Cent Browser? very customizable, but somthing disatended and outdated

UR? The french browser may be a good privacy oriented browser, better than Brave, but it’s something outdated and closed source as Chrome itself

Some minority browsers with other engine than Blink, Gecko or WebKit’ I use Otter and Pale Moon, but only for test reasons, because they lacks of some incompatibilities.

KDE tried it with browsers with WebKit and Qt engines, like Falcon or QupZilla, but without a big result.

Min Browser, very fast and lightweight, maybe good for old PC with few resources, but lacks of any settings posibilities, it’s a window with search engine (DDG) and little more.

There are also some other browsers for enterprise use, with own engines, but paid and closed source.

Maybe Beaker Browser can be used as second (experimental P2P browser), with interestings features, but very special, good for webmasters.

Some text based browsers, like Lynx? Maybe only usefull for some tasks

A lot of others discontinued, like the Tri-engine Avant and more than 70 others.

All of these i’ve tested, also Firefox, and I know why I say that Vivaldi currently is the only alternative.