Okay iced. You can keep trying to convince me that my fluent Hebrew didn’t help me in Yeshiva at all, but that won’t change the reality that all the American kids in the beis midrash always came to me to translate the hard words for them. You obviously don’t know Hebrew well enough to discuss it with any credibility.
Also, just because people understand Yiddish doesn’t mean that that’s the only language they understand. There are not many people who speak ONLY Yiddish, and the ones who do usually live in insulated communities, as I said. Usually, even those people will understand some Hebrew, if you speak slowly enough for them.