I think you mean "running your own recursive resolver", an authoritative server is one which is authoritative for some zone (e.g. example.net), whilst a recursive resolver is one that goes and walks from the root of the DNS hierarchy to the leaf that you have queried.
It is probably quite a bit slower though needing to have roundtrips at each stage of the resolution, which is also likely a reason that these public resolvers get so much use (latency improvement via caching).
It is probably quite a bit slower though needing to have roundtrips at each stage of the resolution, which is also likely a reason that these public resolvers get so much use (latency improvement via caching).