Board Thread:General Discussion/@comment-176.78.141.165-20161006183419/@comment-25893909-20170126134451

Bottom line, neither Goku nor Superman (from the Post-Crisis era or the New 52 era) are limitless. Sure, Superman can pull off limitless feats, but only if given enough time and plenty of yellow or blue sunlight. Remember, without yellow sunlight, Superman can't breathe in space either, just like Goku and Saitama can't breathe in space. Also, if anything, Superman's durability is not limitless. Remember, Superman died by Doomsday's hands. See this: http://static.comicvine.com/uploads/original/11111/111114806/4824364-8353043068-15%252B-%252B1

Same goes for Goku. If he trains harder and is given plenty of time he can easily surpass Superman whenever he wants. Both have lost battles, both have died (Goku died more times than Superman and Three Supermen from three different eras died, in this case, Gold Age Supes is dead thanks to Infinite Crisis, Post-Crisis Supes was resurrected from the dead and New 52 Supes is permanently dead due to kryptonite poisoning) and both came back stronger, but still having fluctuating powers.

Saitama, however, removed all of his physical limitations. PERMANENTLY. Meaning, he has no limit anymore. This is why he no longer needs to train.