Indeed, but as The Onion argued in its recent amicus brief to the US Supreme Court, there is often social value in saying false things "with a straight face": https://www.supremecourt.gov/DocketPDF/22/22-293/242292/2022...

The contrast between what is said, facetiously, & what the reader knows to be true, or discovers as the joke becomes clearer, become a unique & essential part of the expression.

Roe Jogan interviews Jeeve Stobs.