Typescript is a bad introduction to the world of static types in a lot of ways. Typescript is incredible for what it is doing, but still, at its core, laying down a static type system on top of a language ecosystem that was dynamic for years is fundamentally just, well, a bit whacky compared to a language ecosystem that was static from the beginning.

I've been doing Typescript now for about 9 months, so I wouldn't call myself an expert in that, but I also have decades of experience in many other dynamic and static languages (including Haskell), so I can say with confidence that a lot of features in Typescript are to solve problems unique to the Javascript world, and then there are the features in Typescript that are there to solve problems in the other Typescript solutions, and all-in-all while it has great utility and has many fantastic features it just isn't possible to completely overcome the fact that it's a static type system, on top of a dynamic type system.

I've seen a number of posts to the effect of "I'm coming from Typescript and learning Go, how do I do X" and so often the answer has been "Even in Go, even with its very simple type system by static language standards, the answer is that you don't do X at all because X is a feature on top of a feature on top of a feature designed to deal with being on a dynamic language and when you're on a static language you not only don't deploy that solution, you wouldn't even have the problem that's the solution to except that you just created it for yourself by copying Typescript too closely in some other way." A simple example being you don't ask how to type a map/dict/etc. in a normal static language based on the contents of the "type" value, you just declare a properly-typed value in the first place and always use that, at most converting at the edge.

Typescript is a great tool but a very unrepresentative view on how static typing works.