Instead of pleading to the TypeScript gods, why not make a deal with the JavaScript deities? Let's get type-checking into JS!
If I want runtime types, I reach for type guards. If I need to do this a lot, then I reach for io-ts or zod and pretty much exclusively write types as validators/codecs/schemas or what-have-you.
I don't think TS - as a specification, type-checker, community, or otherwise - needs to concern itself with runtime validation UNLESS JS gets some agreed upon way to do it.
If I want runtime types, I reach for type guards. If I need to do this a lot, then I reach for io-ts or zod and pretty much exclusively write types as validators/codecs/schemas or what-have-you.
I don't think TS - as a specification, type-checker, community, or otherwise - needs to concern itself with runtime validation UNLESS JS gets some agreed upon way to do it.