Is this really necessary?
If you want to understand real german as it is spoken between natives and if you want to understand movies and books, even such expressions are important.
Despite the fact that this isn’t really the most beautiful expression.
I think this stuff is critically important. One of my “beefs” with the way language is taught in a lot of settings is specifically that it omits this kind of stuff.
I’ve been to Germany three times and each time, I ended up in settings where people were using words and expressions like this, and I wasn’t in a great position to follow the dialogue.