That would have to be absurdly obscure. Case in point: even Hirokazu Koreeda’s “Distance” has translations available in most languages. I can’t even find art films that lack translations.
Lots of Chinese stuff that lack subs. Often it’s only available on bilibili, too.
I mean, even if something has no subs I think if it was important enough I would watch it anyway.
I’ve watched a handful of Takarazuka Revue play recordings with no English translation. They were adaptations of stories I was already familiar with, so that helped.