I’d say that TypeScript removes friction in the sense that you can use autocomplete fairly easily with it, out of the box. Using autocomplete without type annotations is pretty hard.

OK but then that's ... not actually a criticism? And when the person I replied to says, 'doesn't address issues of the language itself', that's not actually even accurate. TypeScript addresses several large sources of errors in every codebase, like null or undefined errors.

Also, things like automated/safe refactoring, jump to definition, find all usages, etc.