My experience here is very limited, but at least in the Rust world, some ECSs seem to make component dependencies explicit, partially to support scheduling parallel systems execution. That is, if there are two systems where neither system writes any component that the other accesses, they can run in parallel. Is that not common in general?

Godot usually gets a lot of praise of HN and elsewhere, probably rightly so. But I got the same weirdly defensive vibes from reading the article. Performance is the strawman used throughout: claiming you don't need that many objects anyway, claiming that there design is "higher level" -- without ever really explaining what that means. I know from other contexts that the real problem with deep inheritance hierarchies often is code duplication, you simply can't solve the diamond problem. Good job pointing out examples of that.