Hide the entire public guest list

Open Events → Events → select your event → Edit Event → Sharing.

In event Sharing, clear Display Guest List for Event, then save and preview. The setting controls the public list on the event landing and registration-confirmation pages; it does not delete staff registration records. When the list is enabled, the registration interface offers Exclude name(s) from the public Guest List. There is no separate require-everyone-to-be-public control in that interface. Do not clear existing anonymity choices merely to make an event look better attended.