SciHub mainly redistributes scans of print archives made by JSTOR and other organisations. And it does not have everything that JSTOR has. For example, this paper is not, as far as I can tell, available on SciHub:

https://www.jstor.org/stable/4178697

Somehow, you appreciate SciHub without appreciating one of the organizations that did the actual work necessary to make many of those PDFs exist in the first place:

https://about.jstor.org/news/jstor-and-apex-covantage-mark-2...

Are you being intentionally obtuse?

If the JSTOR copy didn’t exist, the pre-print copy would be scraped from the author’s website,

or the text / results submitted by the author or someone close anonymously.

Less, more slowly, but the same point.

Sure, we’ll scrape journal articles from the 1950s from the authors’ websites...

Many more recent articles also aren’t available on the authors’ websites, such as the one I linked.