iOS 14 Messages: no way to add contact to group chat?

So Apple has various online instructions (like this) of how to add a contact to a group chat in Messages. But what I simply cannot find a way to do is to take a Messages chat I’m having with somebody and add a contact to turn that into a “group chat”. There is simply no “Add Contact” button in the Info section of that chat thread. All parties are on the latest iOS 14 and using actual iMessage, nobody is SMS-only so I don’t see any obvious impediment. Am I missing something here or can you simply not turn a 1-on-1 chat into a “group chat”?

I think that 2-way chats and groups are treated differently.

A side effect is that I cannot leave a 3-way group chat. Because then it’d become a 2-way chat.

But I can leave a 4-way group chat.

Unless there is some hidden way I have not discovered, you have to start a new chat and add the additional users at the beginning.

Thank you both.

Bummer. So what’s the logic behind 2-way vs. group chat?

One is company and the other is a crowd?


This likely has something to do with the exchange of encryption keys that underlie each chat session.