It feels slow because UI is not native. Chrome, Safari, Opera have native UIs on macOS. I mean they are rendered by macOS instead of browser engine. You get 60

It feels slow because UI is not native. Chrome, Safari, Opera have native UIs on macOS. I mean they are rendered by macOS instead of browser engine. You get 60 fps for every action which doesn't happen with Firefox. Maybe they should use a process just to render the UI.