Apart from a few obvious candidates (Fawlty Towers, Fools and Horses) most comedies "show their age" over the years as they reflect the attitudes and situations of the time they are made. Indeed, the fact that they no longer appear as funny or relevant in the modern world could be seen as a back handed compliment to the creator as it shows they got the style and humour precisely right for the period in question.
Even something like the Young Ones, which everyone fawned over in my school days, looks dated now and doesn't make me laugh as much as it did when it first went out in the 80s.
IMHO of course.