I don't think so, only if they need to have a schedule as well. Most OSS projects operate as Kanban and it's just fine.

Waiting on a dependency is kinda like waiting on a lock held by another process in the operating system. It has little bearing on whether dispatch queue is effective or not; in fact, it shows the solution: Do something else instead of waiting. (This is why the OS analogy is so useful for project management, if only PM's would listen!)

It's again, if you need to plan things ahead (for some reason) when the dependencies become a problem.

But maybe I misunderstand what you mean, if you still disagree provide a more specific example.