Typescript is flawed, but it is a godsend compared to using straight JS. You can use it like Java until you can't. And then you are forced to muck around with JS hacks just to please the transpiler.

Usually that happens using generic types. They are almost completely worthless in Typescript, and have no analog whatsoever in JS. So you are mucking around just to please the transpiler but adding a type unsafe hack anyway in place of a generic argument.

Typescript should have just stuck with providing checks on type declarations. That's it. Stop adding features from Java/C# when they make no sense in JS.

I would pick another language in a heartbeat, given a choice.