[kabes]

I don't care what svelte does, but I've maintained projects with jsdoc types and projects using ts directly and IMO using jsdoc tends to be more of a hassle to maintain, had worse ide guidance and in general felt just more cumbersome.

Being able to click through to the implementation in your ide is nice though, but can be solved by the ide.

[cxr]

Synthesizing the JSDoc-formatted type information into a TypeScript-like syntax for those who prefer it can also be solved by the IDE.