Lemme break it down for you:
- Having one good corner thing doesn't make you top tier
- Everyone has good corner damage, again this doesn't make you top tier
- Superman doesn't have the best mobility or the best pressure. In the words of a certain nerfed character from another game- "No chance"
- I can't really comment on air-to-airs since I haven't looked into it myself but refer to Everlast's answer
- His zoning isn't "amazing" it's ok. Yes db3 does a lot of chip and is neutral on block but you can duck it/jump over it and eye lasers are punishable/negative
I by no means said anything about him not being good, he still has good damage and mixups and whatnot, but he's just not what he used to be. Then again I'm some 'random scrub' of course so if anything I've said here is wrong then please Supermains by all means explain why