Google Messages is testing a new feature that will help you distinguish between RCS and SMS chats.
Google Messages' latest experiment makes RCS chats stand out in the home screen : Read more
"As it stands, RCS chats are already far ahead of traditional SMS in terms of features."
Featuritis strikes again. The same reason phone reviewers blather on about the most inane of things and phone manufacturers add completely useless cameras to phones that take terrible pictures (so they can check a box in a review).
Sure, RCS has lots of features on paper but they don't work IRL.
The problem is that RCS requires cellular data and until cellular carriers treat RCS communications as distinct from regular data consumption there's a whole lot of drawbacks to using the protocol.
Given that cellular providers don't seem to be treating RCS as distinct from regular data it's a protocol that's dead in the water. I've always got it turned off because the only thing Google Messages on a Pixel is good at with RCS is not sending or receiving messages.