Here's the straight answer: for anything beyond a throwaway script or a tiny prototype, TypeScript is worth it. The costs are real but front-loaded and shrinking; the payoffs compound as the codebase and team grow. The interesting question isn't whether to use it — it's understanding exactly what you're buying and what you're paying, so you adopt it with your eyes open.
What you're actually buying
TypeScript's value isn't just "catching bugs," though it does that. The bigger wins are structural:
Refactoring confidence. Rename a function or change a data shape and the compiler shows you every place that breaks. On a large codebase, this turns terrifying changes into routine ones.
Self-documenting code. Types are documentation that can't go stale. A function signature tells you what goes in and comes out without reading the body.
