It is only the Telegram marketing machine that act that group chats is some special edge case.

It is a case that doesn't fall into "end to end" definition by default because in group chats there are more than 2 ends. Any implementation of group chat like that would be structurally nonstandard.

But if you must have it spelled out, here it is:

Thanks.

Now you are just making things up.

Just google "can't leave group chat" or something.

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

It is exactly about that, otherwise I don't see why would anyone care. Having grown up under a police state regime I live under assumption that the surveillance is everywhere anyway. Don't mind feeding surveillance capitalists with my messages, knowing how many options I have to make them choke. I know that if someone wants to cause me any problems, neither Telegram nor Signal would prevent that.