Earlier quoted context omitted.
What's Crystal's unique selling point? It's older than Rust, Kotlin, Swift, Nim, or even OCaml, and doesn't really offer anything they don't. More Ruby-like syntax? Fine, but most people don't particularly like Ruby syntax.
> It's older than Rust, Kotlin, Swift, Nim, or even OCaml, and doesn't really offer anything they don't. Crystal is only five years old. Nim is 11, Rust is 9, Kotlin is 8, OCaml is 23 and Swift is 5. Basically, Crystal is tied with Swift as the youngest. What it offers right now is a simple porting process for those with Ruby codebases.
But, yeah, besides the syntax familiarity for Ruby programmers it doesn't seem offer much that the others do.