Why the named link matters
A public link is easy to send and impossible to trust. It leaks into group chats, gets reposted, and tells you nothing about who intended to come. A personal link, one per registrant, changes the whole shape of the evening: you know who claimed a seat, you can remind exactly those people, and the list you built from the email is the same list you read afterward.
That is what turns an invitation into something with an ending. Instead of polite silence after you hit send, you have names, a count against your capacity, and a clear sense of who the session is for.