This depends almost entirely on the type of comedy. Things like reference, satire, or shock are obviously dependent on the specific context of time in which they were made and of course become less meaningful as times change.
But comedy is not inherently less "timeless" than any other art. Who's on First is genuinely still funny almost a century later.
The little bits of surviving ancient comedy may seem trite but being simple does not make the jokes less "timeless".
Indeed. In the same vein, Jerome K. Jerome's "Three Men in a Boat" has made me laugh out loud more than a century after it was originally written.
That said, Shakespeare's humor, as an example, lands more flat with me. English idioms and grammar have changed quite a bit since the 16th century, and though I can intellectually approach his plays and recognize the humor, I rarely laugh out loud to it because there's additional mental load required just to understand what's been said. I suspect that may be true of "Who's on First" in another couple of hundred years, too. I'll report back in 2224 and let you know!
I tend to agree that Who's On First is a exactly the sort comedy that will lose its pithiness in time, moored as it is to the cultural context of baseball and contemporary English wordplay.
One of my favourite lines is from Three men in a Boat: "George has a cousin, who is usually described in the charge-sheet as a medical student, so that he naturally has a somewhat family-physician way of putting things".
This depends almost entirely on the type of comedy. Things like reference, satire, or shock are obviously dependent on the specific context of time in which they were made and of course become less meaningful as times change.
But comedy is not inherently less "timeless" than any other art. Who's on First is genuinely still funny almost a century later.
The little bits of surviving ancient comedy may seem trite but being simple does not make the jokes less "timeless".