Nerd here, so I tried to use Lemmy’s API community list with sort=Old parameter in order to try and find the oldest account ever through the oldest community ever. However, it seems like the published property throughout the responses isn’t as realistic as I expected them to be, as there are communities supposedly published in the 2000s. Lemmy itself was initially released in 2019, therefore, the oldest account would be expected to be from 2019 (or earlier, as Lemmy’s development was probably ongoing before 2019). It wouldn’t give a clue on the person’s age.