It would be, but IME Crystal, or statically typed programming languages that don't have a type system at least as powerful as Haskells in general, don't get anywhere remotely close to that, and the overhead added to get what they do give is of dubious net benefit outside of large projects.

And even with Haskell, while you can express a much richer set of constraints in types, there's also more space for bugs in the type level programming.