Same sentiment here. Coming from Opera (in the days it had its own engine) and having been using Vivaldi as my daily since its first public preview, native mouse gestures is the thing I miss the most from Firefox.
I know that the folks at Vivaldi are pretty strongly against the manifest v3 thing, but seems like at one point they’ll have to fold.
I’m a hobbyist photographer. Facebook and Instagram are my main outlets to show off my work right now. While (fortunately) my livelihood doesn’t depend on that hobby, I’d still rather have the online presence.