I mean, I like Firefox, but I’d love to see Vivaldi based on Firefox/Gecko. There’s Floorp, which is similar in some ways but it’s more like an Edge built on Firefox than Vivaldi.
Edit: Thank y’all for your answers. :D
I want to link !@[email protected] 's post because it is a similar quesion. https://thelemmy.club/post/718914
The main reason I’ve heard is that chromium is far easier to embed than Gecko. Gecko isn’t something you embed like a library. It’s something you build upon. Detaching Gecko from Firefox UI (or Thunderbird for that matter) is supposedly really hard.