It would be even better if Copilot was able to make use of the strict typing to prevent generating code that doesn't typecheck in the first place, to be honest. Copilot as-is actually feels more useful for dynamic languages, because static languages get really far without any LLMs and simple static autocomplete gets you really far. So there's more ground to make up.

In addition, Copilot benefits from a large training set, which I guess is best for Python and JavaScript as two very popular languages. Strictly typed languages seem like they are generally less well represented, at least among public GitHub projects.