I would love to see an article that breaks down clustering v. supercomputers v. mainframes in tangible use-cases. It is all a bit opaque to me where one officially starts and the other one(s) begin. As well as where (and to what degree) the value prop is of one versus the others.

I've heard folks say mainframes are just legacy stuff carried forward - I've heard others say they have specific use-cases that are not well solved by other current technologies (usually a cost of refactoring). That said, are there any current use-cases, where if I were to write code from ground zero, that are best solved on mainframe, hands down? That is my root question.