There’s another good reason to have Yiddish it prevents people from going otd “
Perhaps you are unacquainted with the thousands of European YIDDISH-speaking Jews who actually WERE otd IN Europe, and those who sadly WENT otd after the war (and we cannot judge them). The Zionists who are so reviled by many who post here (for being frei), who were the new settlers of E”Y and built up the Medina, most, if not all spoke Yiddish. Not all Yiddish-speaking Jews were frum, and not all frum Jews speak Yiddish. It still however, has a rightful place among things that we should always respect in our history.