Meta: I'd not realised that Sci-Hub was a permitted site on HN. It appears that it has been since at least 2019 looking at the site submission history link.
With regards to mobile browsers, this can be mitigated with charitable practices similar to paywall avoidance, where a considerate user could reply with the direct link to the PDF. This is not necessarily easy on sci-hub (you have to do some poking around with your browser's dev tools), but can be useful if the DOI is queried in Anna's Archive.
This specific paper isn't available on AA, but to whom it may intrigue I think this works:
I'd discussed HN's linking SciHub directly with dang back in 2016, at which time his response was "I think that degree of anthill-overturning would be past prudent."
"Sci-Hub is a shadow library website that provides free access to millions of research papers, without regard to copyright,[4] by bypassing publishers' paywalls in various ways."
(The /r/dredmorbius links in the comments linked above may be seen at the Internet Archive, as that subreddit has been taken private in protest of Reddit's recent policy direction.)
I'm not in the least displeased to learn this.