“That’s why IMO there is no purpose to learning in Yiddish nowadays”
I would disagree as there are at least two very important sefarim in Yiddish: Tzena Urena and Orchot Tzadikim.
Similarly, it would be better to learn the Meam Loez in the original Ladino.
Similarly, it would be better to learn Emunot v’Deot, Chovot HaLevavot, Kuzari, and most of Rambam’s works in the original Arabic.
Similarly, it would be better to learn R’Hirsch’s works in the original modern German.
How many yeshivot teach Ladino, Arabic, and or German? YU teaches Arabic, Yiddish but not German, modern Spanish but not Ladino. I know of one Orthodox high school that teaches Arabic. Any others?