TypeScript has a marginally weaker type system (it's structural and has soundness issues with variance) and is more focused on being close to JS; it has very good ecosystem penetration (e.g. a lot of libraries publish typescript definitions even if they're not written in typescript). Kotlin is intended as a general-purpose language that can also compile to JS. So I'd say it depends on how web-oriented you are.

Got it, thanks for your summary.