Well execution pool doesn't even do parallelism really, just concurrency for the most part (thanks GIL). And JavaScript handles concurrency far better than Python; its event loop is designed for just that. JS and Py can also use subprocesses for true parallelism.
C and Java threads are better than Python because, uh, they can actually run in parallel. Rust adds convenience and safety on top, plus its own event loops. Golang has Goroutines. Erlang has some very powerful solution that I don't remember.
IDK about PHP and Perl, barely touched them. Maybe they're worse than Python for this. Everything else isn't. Python was not originally built with these use cases in mind, which is totally fine, but I'm not going to pick Python if I'm doing complex concurrency/parallelism. For simple process pools, Python is good enough.
C and Java threads are better than Python because, uh, they can actually run in parallel. Rust adds convenience and safety on top, plus its own event loops. Golang has Goroutines. Erlang has some very powerful solution that I don't remember.
IDK about PHP and Perl, barely touched them. Maybe they're worse than Python for this. Everything else isn't. Python was not originally built with these use cases in mind, which is totally fine, but I'm not going to pick Python if I'm doing complex concurrency/parallelism. For simple process pools, Python is good enough.