An NFC ring can still require secondary authentication (e.g., pin) in some contexts. That would be application-dependent.

There are cases (e.g., mass-transit turnstiles) where this isn't desirable --- the intent is to maximise throughput. (The quesiton of whether or not validating or fares are a net benefit is also open.)

For a more secure facility, or payment system, tag + pin (and potentially other identifiers) would be preferred.