It's hilarious how many fanboys are quick to jump on the notion that either Supes or Goku could take on Saitama when they have no freaking clue what Saitama's limits are like the rest of us.

It's a dumb argument anyway, despite their ludicrous power Goku and Superman are still designed to have to face and overcome adversity.

The whole point of Saitama is he's so broken that literally no opponent is a challenge to him and instead the series is about him having to deal with that fact, the people around him who actually do have to face adversity along with their own issues and how he affects those around him.