ReScript solves this problem with a much much simpler type system and stronger inference at the cost of forcing you to handle nulls and undefined as Options. I

ReScript solves this problem with a much much simpler type system and stronger inference at the cost of forcing you to handle nulls and undefined as Options. I get that typescript's decision was to model js's behavior exactly in the type system. But now having seen the costs of that and how much can be gained by relatively small constraints on js I think it was a mistake.