[storafrid]

Certainly advanced, but not mature in my experience. Using e.g. classes and inferred generic function arguments, quickly reveals a lot of features that are missing. Often some similar feature is present but it lacks depth/completeness. Lots of good discussions to read in TS repo on GitHub if you're interested: Optional generic type inference, extends oneof, generic values, keyof a subset, conditional types, etc.

I want to emphasize that the reason we keep running into "ceilings" is probably because of its advanced type system. Libraries and frameworks are using those type features and when we can't keep building on the type - we end up casting to unknown and reconstructing it. Which feels worse than not being able to construct that complex type at all.