ну это так себе аргумент =) c jsdoc ты напишешь просто в два раза больше кода при том же или хуже выхлопе
TypeScript users often complain that JSDoc comments are more verbose than TypeScript types. They are, but for a reason. They provide more information, such as a description of what the types are, what a function does, etc. This provides richer IntelliSense than just types. TypeScript definition files use JSDoc comments to provide the great IntelliSense in IDEs that TypeScript users brag about. Putting JSDoc comments in JavaScript gives you the same experience, but it’s in place where its relevant rather than in a separate file.