They updated it in September:
Family Sharing enables you to play games from other family members’ libraries, even if they are online playing another game. If your family library has multiple copies of a game, multiple members of the family can play that game at the same time. For a more detailed look at how Family Sharing works, see the FAQ below.
Master@lemm.ee 4 days ago
It lets you play a game on your account while someone else plays a different game from your account. Its literally the solution for ops issue.
Buffalox@lemmy.world 3 days ago
I just enabled family share with my wife, but none of us has the games of the other?
And there is no hint of why?
Buffalox@lemmy.world 3 days ago
Sorry, there apparently was a second mail the joining party needed to confirm, works now! 👍 😎 😋