Does JSDoc even have a type checking system? The point of TS is that is actually does something with your declared types. JSDoc is nice... for docs being interpreted by a human. But unless those are used to create red squigglies then it's kind of arbitrary.

I've used JSDoc with TS's type syntax and typechecker in JS files. Which is fine - I find it subjectively uglier but I know some prefer it. But it's still TS that's doing the actual work of determining if all my annotations are compatible when the rubber hits the road.

JSDoc provides the exact same level of type safety as TypeScript, because the TypeScript Language Server/CLI themselves are what does the type checking. Using JSDoc removes the need to transpile your code before executing it. You still want to type-check your code (with a `tsc --noEmit` or similar) in CI, just like you'd run unit tests/a linter/etc.

Yes, that's my point. JSDoc isn't an alternative to TypeScript if you want your types to actually be checked.