I think the real problem is that teams have adopted Typescript because they read a blog post that told them to, not because they fully understood what they were getting into. I expect that these libraries' popularity will fall a bit, because library types need to be very flexible, which means generics, often complicated ones. If they can't easily/quickly write those types with TS, it seems unlikely they'll be able to do it in JSDoc. There are a lot of teams out there that are committed to TS, rightly or wrongly, and if libraries don't provide types or the types are insufficiently helpful, TS teams will not use them.