Thanos Was Dumb

Why did no one ever mention to Thanos that killing off half of everyone would just be a 60 to 70 year delay and after that time has passed, the world and the universe would be exactly where it was when he decided to snap his fingers? Was he too dumb to see the futility in his plan? Did not a single minion of his not see it?

Thanos was not a monster for wanting to save the universe from over population. He was a dumbass for not seeing how his plan to fix it was asinine. Sadly, he is one of the more thought-out villains from movies in recent decades. Most just want to hurt people for fun, or are driven by sheer selfish greed. But in the end, Thanos was just dumb.