It doesn’t say it works for group chats. It says all messages send between iMessage users are end to end encrypted. That, of cause, also goes for group chats. It is only the Telegram marketing machine that act that group chats is some special edge case.

But if you must have it spelled out, here it is: https://support.apple.com/en-gb/guide/security/sec70e68c949/web

I got some complaints from people unable to leave conversations if they have less than 3 or 4 people, which suggests there are technical differences in how they work with many people. It’s logical to suggest the switch from e2e to shared keys happens there.

Now you are just making things up. Apple explicitly write in their documentation, that this is not the case. So again, you suggest they are lying without any proof.

You choose to rely on a service’s promise that it doesn’t host your data. I prefer relying on my experience which says dangers from individuals and conversations are more grave and more likely to be triggered than dangers from services those are being hosted on. I can’t imagine anyone would benefit from spending time on reading or processing my conversations anyway.

I see, you don’t understand the nature of mass surveillance and surveillance capitalism. It’s not really about individuals reading specific conversations…