Librewolf, Vivaldi, Orion (iOS and macOS only) are all solid options.
Librewolf is based on Firefox. If Firefox dies then Librewolf is done as well.
Orion is Webkit-based, which is not too bad, but as you said it's ios and macOS only.
Librewolf, Vivaldi, Orion (iOS and macOS only) are all solid options.