Legitimately curious. Considering Firefox Quantum was released in 2017, is it even possible that my M1 is running any other version of Firefox? Doesn't seem likely considering the copy on the Mozilla site [1] for Firefox Quantum:

> Firefox Quantum was a revolution in Firefox development. In 2017, we created a new, lightning fast browser that constantly improves. Firefox Quantum is the Firefox Browser.

[1]: https://www.mozilla.org/en-US/firefox/browsers/quantum/

Firefox has shipped Quantum in mainline for years. It may be on Chrome's level (I never tested), but regardless, it's nowhere near as performant as Safari.

Try running a very compute intensive script (that chokes your CPU/GPU). In my experience Firefox becomes unusable, Safari is still buttery smooth.

Now maybe Safari simply performs better, or maybe that's some OS level prioritization unfairly advantaging Safari, but to me as an end user, that's irrelevant.