They’ll never open the API, they closed it specifically for control. This has been their Android plan all along, and why AOSP slowly loses more and more functionality with each release. They wanted the perception of “open” while actually ensnaring users.

Best to abandon carrier messaging at this point except as a last resort and use something decent like Signal that doesn’t leak telemetry to Google.

Android really should be divested from Google due to conflict of interests. They will never have users in mind when data mining is the top priority.