I think there’s a differentiation here between a local DNS cache (which does exist on some consumer operating systems) and a local recursive resolver. The form

I think there’s a differentiation here between a local DNS cache (which does exist on some consumer operating systems) and a local recursive resolver. The former lets the system reach out to an upstream resolver and caches the results. By contrast, a recursive resolver is responsible for starting at the root zone and recursing downward from there to resolve the requested domain (so when processing a query for “foo.example.org”, the recursive resolver queries “org”, then uses the NS records returned to query “org.example”, then uses the returned NS records to query “org.example.foo”)