Yeah, you're right, and since vanilla javascript does have runtime type validation that's a reason not to use Typescript. /s

The documentation, tests, breaking run attempts when developing, and flipping back and forth between different source files it replaces, almost painlessly, are 100% worth it.

And you can trivially "nope" out of it anywhere you want if it's getting in your way too much, and congrats, you're back to lovely, pain-free, JS. /s