It's certainly more verbose but certainly not a limited subset. You can copy paste any typescript Type or Interface in a jsdoc @typedef. As I stated in the article, it's still the TypeScript language service that's analyzing either JSDoc-defined types or TypeScript defined types. It's typescript all the way down

But JSDoc lets you do pretty much everything that isn't a runtime feature of TypeScript (e.g. enums, namespaces, etc). Even generic slots are supported

You just haven't worked in a complex enough project yet.

I found several limitations and already opened several issues on github.