RCS (Rich Communication Services) deployment over the last 3 years seems to have been progressing at a snails pace. Just recently, the big four US carriers announced the formation of the “Cross-Carrier Messaging Initiative” (CCMI) with the goal of bringing RCS to Android by 2020. Most frustratingly, there are plans for a new app and the carriers don’t seem to be collaborating with Google at all.
Today, however, a group of Redditors (u/sh0ch, u/LinkofHyrule, and u/NashRadical) discovered a back-end workaround to enabling RCS on any carrier and device. The steps are fairly simple too.
You’ll need the latest versions of the following apps. You may also need to enroll in Messages beta.
I can confirm this worked for me on my own Pixel 2 XL on AT&T. This also goes to show that there has long been a literal switch that Google could just enable to give everyone using the Messages app RCS.
Source: Reddit