even though I am guessing that with a better webassembly support of the browsers

Considering V8 overcame python in benchmarks nearly a decade ago, I'm not sure even some miraculous webassembly environment would put python faster than javascript in the browser of all places.

V8 does not quite compete with the big guns in the space (C, Rust, Go), but now that it's only 2-4x slower than C++, it's created this niche of "almost hardcore fast" for javascript that is just unlikely to be dethroned any time soon.

People fail to quite get how many leaps and bounds V8 has taken in the last 10-12 years. Javascript's reputation of being "scripting language slow" is simply no longer the case and hasn't been for an entire Era in software terms. Reasonably-written Javascript is now often faster than heavily-tuned Python, and well-written javascript is faster than reasonably-written C++. It's not necessarily fair (like comparing modern solar to nuclear, with the absurd amount of money that's gone into solar research), but I don't see it changing any time soon.