Re: Please, Firefox, just go away already!
I have a relatively new machine, and haven't run JetStream2 before, so just gave it a shot on Safari, Chrome and FirefoxDE (my daily driver). Safari is ahead by a good margin (172.9) from Chrome (150.0) vs FirefoxDE (91.6). The nice thing about JetStream2 is that it reports good statistics about all of the component tests, and the differences are interesting. SpiderMonkey actually wins a few rounds (eg regexp), but there are others (splay, which is claimed to be a heavy test of the garbage collector) which it loses to Safari by a factor of nearly nine. Mostly its behind by a factor of about two, which is further than I had thought.
And yet it's perfectly fast enough for me, and what I use it for. I suspect that the multi-threaded layout engine from Servo probably helps more than the last percent of wasm performance, most of the time.
And none of that is why I use Firefox. I use it because it's the hold-out for ecosystem diversity, because it runs on all of the platforms that I use, and because the sync protocol that gives me a uniform auto-fill and access to all of my cross-device tabs is client-side encrypted.