JSDoc *is* TypeScript

JSDoc is not an alternative to TypeScript but rather a way to use TypeScript itself. The TypeScript language service powers IntelliSense and interprets JSDoc comments, meaning developers using JSDoc are already using TypeScript without a build step. The Svelte team's 2023 switch from .ts files to JSDoc wasn't anti-TypeScript but a different approach to the same static analysis. JSDoc offers nearly all TypeScript features (except runtime features like enums), provides better code navigation by jumping to actual implementations instead of declaration files, and works with existing TypeScript tooling including type generation libraries.