Union types are a gap, although records and switch expressions will get you much closer than was previously possible.

Object literals are a thing, they’re called anonymous types. You just new them up. And functions can be passed around as first class objects, with some minor type boilerplate in a few places.

There are a few places where you have to adjust to different naming conventions and types are obviously stricter but my experience is that for the most part modern c# has all the things I like about TS/JS.