I know there are plenty of esoteric programming languages that are designed to be incredibly difficult to work with, like Malbolge, Brainfuck, and PikaLang, though programs written in them can still be compiled and run by a computer.
There are lots of constructed linguistic languages, like Esperanto and Toki Pona, but for most of those they are designed to be easier to learn or have other functional benefits. Are there any linguistic languages where the goal is to be difficult to speak, write, and understand, while still being actual languages?


Khoisan languages might be in this category.
https://en.wikipedia.org/wiki/Khoisan_languages
Well those are actual languages spoken by hundreds of thousands of people (from what I can tell from the Wikipedia article), they certainly aren’t designed to be difficult to learn. Perhaps it’s hard to learn for people who speak English, German, Chinese, Arabic, Portuguese, etc., but the goal wasn’t to construct a language that is hard to understand.
Damn you are right. Oversaw the “designed to be hard” part of your question.