why isn’t English a holy language?
I think the difference between English and Aramaic, Yiddish, Ladino, etc. is that English is not unique to Jews at all. Even the “yinglish” that many frum Yidden speak is almost the same as regular English, with some minute differences.
Whereas the other Jewish languages that were spoken by Jews who were secluded from the goyim are only vaguely similar to their root languages.
Someone who speaks Yiddish will have a hard time understanding German, and vice-versa.