The erlang case suffers from none of these problems, plus it's even more sophisticated, you can set up failure domains with few lines of code; it's designed for the spawn to be truly autonomous with restart/retry logic, do rpc over distributed systems with unreliable networks, etc.

Once you've spent time working in erlang concurrency, it's hard to believe that this pattern is an advantage except for the fact that python (and go, and js) is designed for linear primary execution flow. In erlang by contrast, a script with a primary flow is a special case of a concurrent system (which itself is a special case of a distributed system).

Addendum: If I'm not mistaken, the nursery concept does exist in the BEAM vm, it's Task.await_many in elixir.