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.
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.