And indeed the Angular documentation does not help at all. It's awfully abstract, and I always had the impression it's trying its best to avoid telling you what you actually need to do in order to achieve X, for most values of X.

This kind of non-documentation, coupled with the fact that Angular is IMO overengineered, drives me crazy.

That's why it's always a good idea to look into other frameworks and languages :)

I had to do some Java stuff in university so I knew the concept of dependency injection. But in JavaScript it isn't used that often.

Probably because "classes" are simply functions there and you can store a function in a variable and pass it around without thinking about its "real" name, which already decouples things quite nicely.

Honestly, I find the official Angular documentation useless until I already know what I want from it and just refer to it as a refresher.