Yes this is where I see Ruby 3 being irrelevant, unfortunately. Ruby and Python are single-threaded, dynamically typed languages designed for the 1990s. You can try to retrofit anything you like and pretend you have real concurrency or static typing but it will never be the real thing and you'll just end-up with thousands of legacy libraries.
I think Erlang is older than Ruby? (Not sure, but it's pretty old!)
As for single threaded, they are not, even with green threads, IO is usually the problem (otherwise you chose the wrong language).
As for static typing, there advantages and disadvantages to that, I wouldn't consider that a minus at all. A good engineering culture brings you in the same place with a dynamic or static typed language. Same goes for a bad engineering culture.
