I'm going to dissent. The difference between ancient and modern comedy is mainly one of cultural translation, not historical change. You can read jokes in the Philogelos whose form wouldn't be out of place in the Borscht Belt. The big difference is, they have slightly different comic types. The skolastikos, for instance, is usually translated as an "egghead" or an "intellectual". But from context, it often seems to mean "absurdly literal-minded", in that computer programmer social cognitive deficit sort of way.

Theophrastus, in addition to his botany, wrote some great little character type sketches. Some of the types are immediately recognizable. Others, you can see all the elements, but the culture is different enough that you don't know why together they form a whole. Commedia dell'arte is the same way. It's not the difference in time that makes them opaque, but the difference in culture.