I agree. Something other people aren't mentioning - the default iOS Contacts app will automatically switch your messaging and voice call shortcuts to use an alternate platform, per-contact. There's no user interaction required to do this. A lot of people in these threads conflate iMessage, SMS, and MMS - the idea that iPhone users are "locked into" iMessage is absurd. This feature has been in place for many years. [0]
IMO, the buy-in for iMessage is an iPhone. If you contrast a $429 new iPhone with the buy-in required for other mainstream apps (share and license your private data + metadata with advertising companies in perpetuity), $429 doesn't seem unreasonable at all; but if you prefer to pay with your data instead, all platforms (including the iPhone) provide an option to do so via options like FB Messenger[1] and WhatsApp[2].
If Apple were to remove these alternative options, along with SMS/MMS, and support only iMessage communication - there would be a much better support for the claim that they "lock in" their users.
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.
IMO, the buy-in for iMessage is an iPhone. If you contrast a $429 new iPhone with the buy-in required for other mainstream apps (share and license your private data + metadata with advertising companies in perpetuity), $429 doesn't seem unreasonable at all; but if you prefer to pay with your data instead, all platforms (including the iPhone) provide an option to do so via options like FB Messenger[1] and WhatsApp[2].
If Apple were to remove these alternative options, along with SMS/MMS, and support only iMessage communication - there would be a much better support for the claim that they "lock in" their users.
[0] https://i.imgur.com/PuPIrvf.png
[1] https://bgr.com/tech/app-privacy-labels-facebook-messenger-v...
[2] https://www.wired.co.uk/article/whatsapp-instagram-facebook-...