You don&#x27;t actually have to use the transpiler features of TypeScript if you set `--target` appropriately. And Flow has the same problems regarding language features. Flow doesn&#x27;t just magically understand all JS features now and forever. When new stuff comes out it has to be added to Flow, same with TypeScript.<p>Edit: To be clear though, I agree with you about the TS transpiler. I think TypeScript&#x27;s strength is in its static type checking, not in its transpiling.