The new type system is a superset of the older ones. You can still write your own specialized error-prone repetitive containers for each and every type by hand

The new type system is a superset of the older ones. You can still write your own specialized error-prone repetitive containers for each and every type by hand. Yet, once a language has generics, people don't use the old way even though it's still possible to. Perhaps that's because it has no place when there's a replacement which is less error-prone, less repetitive, more usable, and can be implemented once in a library and used forever.