I have always been curious about this. Did you get them to use other services or did they stubbornly refuse and you just accepted it? I am talking using Chrome, using Windows, using social media like Tiktok or Facebook or Instagram, etc. Bonus points if you have kids because that is even more work in the privacy realm
It’s not exclusively singular or plural. That hasn’t changed in more than 50 years
the singular use is so old, when it was first introduced, “they” was still spelled with a fucking thorn!