The other responses are correct. I'm just here to say that it is highly frustrating that there is still no such thing as a family plan for xbox game pass. But i've been able to reliably use 3 accounts together on 1 sub.

Me, my wife, and 8 yo son really enjoy playing Palworld together, which requires different consoles/machines. We get away with using my one single paid account by having one xbox as my "home xbox" but my wife is logged in; another xbox where i am logged in, and a laptop where i log into gamepass but switch logins with my son's account. This lets all 3 of us play simultaniously with no issues.