> I haven't been following exact features between browsers too closely recently, but Firefox's Tracking Protection has been around for a while and improving for years; and of course, Firefox is where AdBlock/uBlock originated. What does Safari provide that Firefox does not? How does it affect web compat?
Firefox, like uBlock and AdBlock is list based - it forbids known bad actors. Safari is changing web standards to make tracking impossible, regardless of whether or not you are a known actor, and doing it gradually and carefully enough enough where breakage is minor enough that users don't complain. And Safari has less market share than Firefox. Look at e.g. https://webkit.org/tracking-prevention-policy/ for the principles and the other posts on the blog for details about the implementation. It's an industry wide change that a non-advertising funded browser company needed to push, and it just needed a real leader to push it. And that person turned out to be John Wilander (https://twitter.com/johnwilander). For whatever reason (I've given my thoughts above), I think Mozilla struggles to attract these sort of talented experienced mid-career people.
Rust is pretty cool, but Servo is pretty immature, and it seems like Mozilla just fired all those people. I dunno. I don't see a bright future there.