Jothar – Indeed, Yiddish is not “intrinsically” holy, as is Loshon Hakodesh (which is certainly the loshon of the highest kedusha), it obtained that status by its usage.
Additionally, Loshon Hakodesh was never used by Yidden as an everyday street language of mundane matters. That was Aramaic (indeed another language with great kedusha) or other local languages.
And of course, literally countless Torah was learnt and inscribed in Loshon Hakodesh. (And as was mentioned previously, “ivrit” is NOT Loshon Hakodesh by any means or shape.)