It's not that English can't express some things at all, but that there are words in German that aren't neatly translated to a English word. Schadenfreude is one German word that's been brought over by a certain writer. It's the joy of seeing someone else's misfortune. That's six-words to express what German can do in one, and for a poet or a wordsmith, that just won't do. If you're dubbing a German TV show, how're you going to fit those six words when the a character yells that one word. Smush it in and hope for the best? So it's still translatable into English, it's just clumsy. As are all translations, really. So German isn't special in that regard, plenty of languages share that quality. And no, the Inuit don not have 37 words for snow.

Torschlusspanik is the fear that time is running out for eg a career change. Weltschmerz is a deep melancholic sadness about the state of the world or life. Hopefully someone who actually speaks German can give greater nuance to those definitions and maybe some other examples.