> But not really - for any project of a significant size, sooner or later a build step will be needed for this or something else. Not to mention that many projects are now done in TypeScript, which means there's a build step anyway.

https://github.com/sveltejs/svelte/pull/8569

> As a Svelte compiler developer, debugging without a build step greatly simplifies compiler development. Previously, debugging was complicated by the fact that we had to debug using the build step. In addition, using JSDoc does not affect compiler’s development safety because the type is almost equivalent to TS.

Deno also switched away from using build-requiring TS