Because the bar is low and part of the craftsman's job is to learn their tools. If everyone who wanted to use a computer needed to learn how language servers work, that would be a problem.

A programmer having to learn how language servers work isn't a pain point, it's their job. It takes a couple hours to learn. A couple hours to learn how to do part of your job isn't notable. Complaining about learning how to do one's job makes one unqualified.