It’s not that he’s the only one of the Greek comic playwrights whose work has survived, it’s that he’s the only Greek comic playwright with works that have survived in full. And he’s the one people tend to care about most. We have fragments of other playwrights, we just don’t have full plays. There are two 19th century collections of surviving fragments of the comic poets if you’re interested, but they omit - for obvious reasons - finds that have been made after that date and for Menander in particular that’s actually quite a significant amount.

Menander, who wrote New Comedy, is a playwright whose corpus has been changed significantly by 20th century and later papyrus finds. We have two of his plays for which we have a significant portion of the text and other plays which we now have much greater extant fragments of, thanks mostly to 20th century papyrus find, the mid century Bodmer Papyrus in particular. Of Menander’s Dyskolos, we’re now only missing in their entirety nine lines from the entire play, and there are an additional twenty which are badly damaged but there. The Bodmer Papyrus supplies most of the text, plus a plot summary, a didascalic notice, and a cast list, and we have extant fragments as well. And between the Bodmer and Cairo papyri, 737 lines of the Samia have survived, although a much more significant portion of them, mostly from the beginning of the play, are badly damaged. And for that play, thanks to the very consistent spacing of the Bodmer Papyrus scribe, we know that the play was only 897 lines total, so we know exactly how much we’re missing.

So while we don’t technically have extant a whole play by Menander, we’ve got at least one play that’s only nine lines off and another which we’ve mostly got. We hear less about them in part because of the relative newness of actually having significant extant texts to work with and mostly because, frankly, New Comedy tends to get a seriously bad rap because it’s less overtly and directly political and is therefore viewed as less important than Old Comedy. The view that New Comedy is everyday and therefore trivial is fairly deeply embedded and, even within Classics, Menander tends to be treated as a footnote to life-after-Aristophanes. This means that even sidestepping the problem of what texts we have extant from the comic writers, there’s also an issue of uneven visibility that obscures the fact that we do have an almost-complete play by someone other than Aristophanes.