Structural is not worse than nominal. Nominal types are mostly a lie, and in the case of JS and package managers / module systems like npm / node's, they are a

Structural is not worse than nominal. Nominal types are mostly a lie, and in the case of JS and package managers / module systems like npm / node's, they are a non-starter. Arrays are no longer bivariant, and haven't been for at least a year. They are still covariant unfortunately.