I'm afraid it'll take very, very much time and effort for Ladybird to be as fast as Firefox. Web pages are terrible resource hogs. An inefficient browser will not be popular.
> One of the long term goals is to match the performance of other production JavaScript engines like JavaScriptCore and V8 when they run without a JIT compiler.
https://youtu.be/n4YBMjlGWRc?t=77
I imagine a lot people won't accept that. Especially not as we're shipping more and more JavaScript.