Comment by babuskov

Not really. It still has a library level lock. What Steam Families has enabled is to play games from each other's libraries at the same time. For example, if my account has a game A, and your has a game B, I can play the game B while you play the game A. This used to be disabled before.

You still cannot play a game C from my library while I play the game A from my own library.

The only way to be able to play any game you want would be to create a separate account for each game.