You seem to have no idea what you're talking about. Type theory is a thing, much older than any compiler. And soundness has a meaning.
> It just means type errors are checked at runtime instead of compile time.
This is a fundamental misconception. A type checker proves the absence of errors. It doesn't check for error conditions. That is: A program that isn't (cannot be proven to be) well-typed can very well be correct. But a program that is well-typed is guaranteed to be free from certain errors.
What you call "dynamically typed", in contrast, is comsequent just value inspection and stopping the evaluation/execution early. A program that has been executed successfully often is not necessarily correct.
> It just means type errors are checked at runtime instead of compile time.
This is a fundamental misconception. A type checker proves the absence of errors. It doesn't check for error conditions. That is: A program that isn't (cannot be proven to be) well-typed can very well be correct. But a program that is well-typed is guaranteed to be free from certain errors.
What you call "dynamically typed", in contrast, is comsequent just value inspection and stopping the evaluation/execution early. A program that has been executed successfully often is not necessarily correct.