The US is hardly representative. Globally, 25.3% of website visits happen from a device running iOS or MacOS. That's impressive, but still a mere quarter. Windows (29%) and Android (40%) each account for more users.
Which isn’t actually relevant to any specific website as they all favor either some subset of users and generally a subset of their devices. Ie: Fewer than normal stack overflow users are coming in on cellphones let alone PlayStations.
You need to know your target audience, not simply lookup overall statistics. I’ve seen Windows make up less than 4% of all users and I’ve seen it be over 90%.
Statscounter is a popular statistics for platforma usage, but I strongly doubt that it is heavily biased. I've never found that any websites use statcounter (though I haven't aggressively investigated), and never found installation guide in Japanese. Perhaps is userbase biased to smaller websites on some countries?
https://gs.statcounter.com/os-market-share