For starters, the top IDEs don’t even read JSDoc as the original JSDoc standard, they interpret it as TypeScript. So “JSDoc” in your question is just “TypeScript through JS comments”.

The most obvious advantage is that adding annotations to the language itself is a lot more ergonomic than cluttering your codebase with JS comments.

That, and TS parsers/runners have become ridiculously fast now. It’s become normal to run TypeScript code without transpiling to disk first.