Superman isn’t a god. The definitions of what a god is across cultures are pretty varied, but one thing that pretty much all of them have in common is that a god has authority over at least some part of nature (often being a personification of that part.) Superman has no authority (beyond the trust that humans willingly give to him do to his actions,) he’s just really strong.
The fact that modern writers insist on treating Superman as a god is one of the reasons why so many modern Superman stories suck.
A lot of writers don’t treat it as a joke.