This seems a bit confused. You complain about parallelism, but then raise other languages for their concurrency stories. Concurrency is not dependent on parallelism and indeed Crystal do have a nice concurrency story with fibers and channels that perform pretty well.
Re:Why Crystal Is My Next Language
by hamandcheese on Sunday June 10, 2018 @11:22PM
(#17281506)
Do you need truly parallel processing?
Crystal already has a great concurrency model, it’s just not parallel yet.
It is a gorgeous language, though, with a very easy to read syntax. I'd love using it if it had something like goroutines, which would look great with its block syntax. Good luck to the team working on it; I hope it's a contender.