@WILDKATZ It's not ageism at all, merely trends of comedy and humor styles. They evolve over time, and both late Gen X (Xennials) and Z appreciate a more bizarre "disconnected" style of comedy that, say, my wife, a blatant millennial, think of as utterly ridiculous.
@WILDKATZ Fair example is that I grew up with Tom Green and the Upright Citizens Brigade being TV shows that were incredibly "ahead of their time" and both would have hit even more hard a decade or so later, because comedy trends and styles evolve and adapt... Doesn't have jack shit to do with age. Only has to do with timing.
@WILDKATZ if you really want to force "age" into it, it's simply because of what age we are in our formative years... What's considered "dad jokes" now are simply because that was the style of humor when people who are dads now were growing up ... "Dad jokes" generations prior were what was humor in the 50s, etc. What teens find funny now will be the "dad jokes" in 20-30 years.