That makes sense too.Removing a stone from the timeline creates branch timelines (the Ancient One specifically says this) Thanos and all his people came from a branch timeline created after the Avengers stole the power stone. This branch timeline was then prevented from existing at all when Steve returned the power stone at the end of the movie. Thanos and his army were just killed, and there is no timeline in existence that ever missed them.

) to help you better identify with the movie and provide a suitable romantic interest for the lead female character--that way you will be more likely to sit through the movie when your girlfriend drags you to see it.