Most funny jokes are obvious, at least after the punchline.
I would disagree. Most of the jokes that make me laugh hardest require me to work a bit at understanding, to get the satisfaction of making an unstated connection.
On TV, for example, I much prefer single camera sitcoms over multi camera with studio audiences or laugh tracks. I don't need things to be heavy handed about which parts are jokes.
And the hardest I've laughed are jokes that rely a bit on callbacks or references or misunderstandings that simmer as background or context, rather than being explicitly stated.