No actor-model based language has this problem, so perhaps all it comes down to is baking in the right(or even any decent) concurrency support from the start, at the language level.
Of course they have. Well, everything is nice and dandy until your actors never block. As soon as you start blocking, your async model has the same problems as threads have. And you cannot really write real-life systems without blocking actors.
Ask Erlang programmers whether they have dealt with this kind of stuff.
The main process or any parent process can be made to not block by spawning sub-processes that handle an entire group of child processes , so I don't see how that is a problem.
Ask Erlang programmers whether they have dealt with this kind of stuff.