I don’t know anything about this talk, it’s probably excellent. But there is no way a graph like this can ever be a sign of a healthy system, regardless of what kind of subsystems, modules or services are used. Don’t put yourself in a situation like this if you can avoid it.

Well, the most important thing from my point of view is to slice your domain into self contained modules with the lowest coupling possible.

Yes, but we also have to be aware of evolution that will occur over the live time of our system(s). We should always look out for the moment when changing the module structure and the coupling becomes necessary.