[ImprobableTruth]

I agree that gradual type systems are great, but man, I feel like the expressiveness of e.g. Typescript is fantastic even for 'normal' programming.

Something like fully typed forms (so that e.g. <Input type='text' path='address.street' /> only works if your form data has a { address : {street : string} } + branded types for more custom data fields) is absolutely magical and makes working with lots of highly complex forms a breeze. Tests just don't compare.