It really is terrible at humor. I tried asking ChatGPT some dumb joke questions like "if I melt dry ice, can I swim without getting wet?" Any human being would know that this isn't a serious question and is intended as a joke. But ChatGPT gave me a short lecture on the actual chemistry of dry ice and then clarified how dangerous it would be to swim in or with dry ice. The joke went way over its head.
I asked some other similar questions. ChatGPT has zero sense of humor.
I always thought those examples demonstrated ChatGPT has a deadpan(1) humor, not that it's bad at humor.
1: I had forgotten the term for this and Google didn't help, so, of course, I asked ChatGPT:
Q: "What is the used for the type of humor where someone makes a joke question, and the other replies in a serious and factual manner on purpose?"
A: 'The type of humor you are describing is often referred to as "deadpan" or "straight man" humor. It involves one person making a joke or humorous statement, and the other person responding in a serious, matter-of-fact manner, as if the statement were completely genuine. This creates a contrast between the humorous intent of the joke and the serious response, and can be very funny when done well. Deadpan humor is often used in comedy sketches and stand-up comedy routines, as well as in everyday conversations and interactions.'
* doesn't "care" if its output is true or false
* is weak at humour
which (for the moment) suggests that there remains a niche for people who have integrity and can laugh at themselves.
(Should that niche disappear in the future, at least one won't have lived in a shameful manner before then: