New Avengers theory explains why Thanos waited until now to attack the universe

After 20 movies in the Marvel Cinematic Universe, some fans may be right to ask themselves why Thanos waited so long to mount the powerful attack on the universe that we've just witnessed. After all, Avengers: Infinity War showed us how formidable an adversary Thanos really is, especially after he's able to add more and more stones to that terrifying gauntlet of his. So why not pursue his dream to kill half of the beings in the known universe with a simple snap earlier than that? There's a new t...