I imagine what they mean is e.g. that TypeScript can tell you something is a Date, but it doesn’t attempt to fix some of the confusing, quirky behaviour with that: developer.mozilla.org/en-US/docs/Web/…/Date#inter…
So, yes, it’s generally better than JS, but it doesn’t actually make it good/attractive, if you’re used to the sanity of backend languages. It very much feels like lipstick on a pig.