The advice is sound. Having more written records of such things definitely help teams. It can have a benefit in other forms (notes or todo's) if you do it just for you.

Indeed, in some type of projects people tend to turn to Dependency Injection Frameworks a bit blindly (especially true in the Java world). Still there are other patterns which give similar benefits without less headaches. That's worth investigating if this fits your context before picking up a framework.

I tend to agree with this quite a lot. Git submodules tend to create lots of strange issues and rather bad developer experience. Even worse it's not necessarily spotted straight away, you notice the real pains only after having invested in it quite a bit. There are alternatives worth exploring though.