And Samsung gave up.

Some carriers do, some never did, and some did but gave up. In the end if they want wide deliverability they’ll have to connect to Google’s hubs (servers).

It is annoying that Google doesn’t provide an API for RCS as they do for SMS and MMS.

1.1.1.1 does no filtering. 9.9.9.9 does, similar to 1.1.1.2. To skip filtering use 9.9.9.10.

I expect they think that a significant percentage of people that have Internet also have a smartphone. They probably aren’t far wrong.