What we call the web, surely? I appreciate we conflate the two, but in this context I think that's what was meant.
And it's really the URL (URI, IRI, URN...) that makes the web. An amazing thing.
I get incredibly frustrated with websites (e.g. many SPAs or frontend-happy sites) that don't provide a URL that I can bookmark and share where it obviously makes sense to do so.
Well Chrome devs seem to disagree, with the recent push to hide URLs, and so do SPA devs. Is the article meant to save the URL, or rather a fairwell? Anyway, URLs aren't particularly well-designed IMO, for their use of the ampersand char as separator in the query part alone, since these conflict with ampersand as used for starting entity references in HTML and other SGML docs.
??? - those usually use the URL bar in my experience.
They aren't conventionally "shareable", first off, which violates more or less the spirit of what a URL is supposed to represent on the Web.
I've written plenty of SPAs myself that use the URL and you couldn't actually tell it's an SPA unless you have the technical experience to know what to look for.
If what you're saying is "this infinite-scrolling page sucks at respecting URLs", that's something else, and it's not specific to SPAs. Infinite scrolling predates SPAs (Here is one for jQuery! https://infinite-scroll.com/#initialize-with-jquery), and doesn't have to break URLs if you don't write your code like an uncivilized brute.