[arghwhat]

To clarify: The Digital Markets Act includes a requirement for large message services to be interoperable (e.g., that you can chat with a WhatsApp user from Telegram), but Apple argues that iMessage does not have enough users in the EU to qualify.

Apple might be correct in this regard, as iMessage is not very popular in EU specifically. For this to apply here, either Apple would have to be caught lying about their numbers (not impossible), the EU would have to lower the minimums, or the US would have to create their own counterpart as iMessage is much more popular in the US.

[pmontra]

Everybody really use WhatsApp to send messages to friends here, especially in group chats. I'm using Telegram with some friends and for some groups but WhatsApp is bigger. Anything else is a rounding error.

It's not even easy to know who's got an iPhone now: it's just a big phone with lots of cameras as any other one. However it's likely that two close friends, families, etc all using iPhones could decide to use iMessage for their own messages. Same as for... (had to google it) FaceTime.