TL;DR
- Users who have rooted their phone, have their bootloader unlocked or are using some custom ROMs report that their RCS messages are not being sent, even though RCS shows them as connected.
- The Google Messages app does not show any error messages when blocking RCS messages of these users and does not send the messages out as SMS or MMS either.
- Google famously campaigned for Apple to include RCS messaging in iMessage but is now blocking it for certain Android users.
How is Google going to stop them?
Forbidding an app from the Play Store is unlikely to stop these users, who already use rooted devices and custom ROMs. They’ll just get an app from their ROM provider, F-Droid, or elsewhere.
Does RCS depend on Google services integrated with the mobile network operator? If Google tried to use that position to forbid alternative apps, it would seem likely to run afoul of the Digital Markets Act.
I don’t know a lot about RCS specifically, though. Is there another issue I haven’t considered?
Using RCS requires low level access to phone’s modem. You won’t get it on Android. Google is bypassing it’s own restriction by using proxy servers while having the deal with phone operators.