TypeScript releases are usually incremental, and 6.0 is no exception — but a few changes meaningfully improve inference and performance.
Better inference in everyday code
You will find yourself writing fewer explicit type annotations as the compiler gets smarter about narrowing and generic inference.
Faster builds on large projects
Project references and incremental builds are quicker, which is the difference between a tolerable and a painful monorepo.
Most codebases upgrade with zero changes. Read the release notes for the handful of stricter checks and you will be done in an afternoon.