[somethingsidont]

iMessage is competing unfairly, as the default, pre-installed, SMS-integrated app on iOS. Being hardware-attested and limited to the dominant US smartphone OS exacerbates this.

Most other countries are using some other messaging app, so clearly these aren't super significant hurdles. I agree "lock-in" is strong wording that probably doesn't apply to iMessage. But you cannot argue that iMessage is competing fairly with the likes of FB Messenger / Whatsapp / Telegram / Signal.