Yep 99% of the time (particularly with android) it's the person's personal set up rather than a site fault.
At this present time Pasoti is purring along.
If the browser supports a particular 'setup', and a site doesn't work properly with that setup, then it's 100% the site's fault.
Appreciate what you're saying about not being able to cater for all the edge cases (the least common 5% of configs), but the problem still sits with the site - it's not the user's fault if they're using a supported phone / OS / browser combo, and your site doesn't support it properly.
FWIW I use Android / Brave on a fairly high spec phone (Snapdragon 855 Octa-core, 8Gb RAM). Pasoti used to run perfectly, but the last few months it's been poor. My setup hasn't changed. Other sites continue to work perfectly. The difference seems to be the introduction of new types of ads on this site.