That’s already true for all the Javascript tracking and ads. It seems silly to now worry about a few extra ms that it takes the CSS parser to resolve it’s difficulties.

Maybe if they specified how long this ‘infinite’ lookahead takes in all their scenarios, it would be more compelling.

Tracking and ads scripts aren't special here. Yes page rendering is paid by the browser every time, and this group of people is specifically worried about the CSS part of that process. They're separate concerns and don't need to influence each other design wise

Also, CSS is often used in other contexts than web browsing as well.

Really? I'm not aware of any except exports of the browser stack like Electron.

Really, it's ubiquitous. Qt and GTK use it extensively. You don't need HTML at all to use CSS, it translates well to a lot of other things.

That feels like a very user-hostile point of view. It's better to spend a bit of time to get this right rather than just doing it in a way that affects millions of web users.

Yes but that cat is so far out of the bag that it's meaningless. The browser's model is "ship source code, and we compile and run it." I would love a universe where it would be possible to ship some binary artifact to browsers so that it can load it as if it was an already opened page, complete with local state and skip all the parsing/compiling steps.

Meh - every step down that road has been fraught with significant issues. See: Flash or Silverlight, for example. (Yes, I know, not quite the same as if the browser did it natively.)

One of the beautiful things about the web is the ability to jump into the dev tools and look at the code. I know it's harder than ever to actually learn from that now, and I predict you are correct that someday we'll get to the point where it's a binary blob delivered. But I'm not holding my breath waiting for it and certainly not advocating for it. I'll adapt when/if it happens, but I feel a bit of the "magic" of the web will die that day.