You have a JavaScript application. You have to keep up with stupid devs that don't know TypeScript because you don't have the time to let them study it and they get demotivated when they can't do stuff so fine, you keep it JS. You use JSDoc to write the documentation. You miss using TypeScript so you start doing some @typedef's. Oh your linter gets it and starts behaving as a substitute of TypeScript. You get excited and write more and more @typedef's! ... until they get so complicated that you start documenting *that*...