Why aren't twins called duplets?

[Assburgers2]

[ZanyInternetName]

It just never stuck. Twin originated from the languages brought in by immigrants speaking Germanic languages like proto versions of Danish - traces of this are still found in, say, German (Zwilling shares the same root) or Dutch (Tweeling does so too, retaining the T). The word duplet would be based on French / its ancestors, which arrived at a time when twin and its ancestors already were established.

[Simba4]

Its like pronouncing tens as onety (onety one, onety two, onety three and so on). Its just incorrect

[Saccharissa]

https://www.etymonline.com/word/twin

[Assburgers2]

In dutch twins is tweeling and triplets drieling, this means you know as much as i do that tweeling and drieling, vierling, vijfling, et cetera is determined by the amount of children and no other reason. But why in English must tweeling be twins and drieling triplets? It makes no sense.

[Saccharissa]

Try to not cherry pick one word out of the pile to dismiss the whole concept?

[Assburgers2]

Its probably the same for proto-germanic and the norse languages too or not?