Yes, it's true that jokes often dehumanize, but they sometimes do so in a context that reassures us that we're not supposed to feel sympathy for the suffering person, at least not at that moment. Either their behavior is truly ridiculous, or simply contrary to their stated goals. But needless suffering in itself isn't comedic, I think.

I can't get het up over Zecharias Smith. He appears in HP twice. He's a caricature

Yes, exactly.