> Are these iMessage group chat really a thing?
For some, but everyone knows and has the capacity to download WhatsApp.
The root issue is there is a lot of judgment about Android users, hence wanting to restrict chats to iMessage. It’s a signal that you are part of the in group vs out group.
Although, it is objectively convenient to have a group of all iMessage users at events, because any pics/video get shared at high quality with no extra work.