So in an earlier doc-version, Scripting, I ran across this:
When designing games using the scene system, the whole project is fragmented into complementary scenes (not individual ones). Scenes complement each other, instead of being separate. There will be plenty of examples about this later on, but it’s very important to remember it.
For those with a good amount of programming expertise, this means a different design pattern to MVC. Godot promises efficiency at the expense of dropping the MVC habits, which are replaced by the scenes as a complement pattern.
So what exactly does that mean that scenes "complement" each other? I feel like it means that they are closely coupled - originally I was searching on MVC, which the docs basically say, "don't do that". And of course MVC is about decoupling functionality into different modules.