The only benefit is sending higher DPI pictures between android and ios

After getting several family group chats finally converted over to RCS, one day my phone just started absolutely refusing to verify my connection to the RCS servers. Instead of any kind of notification, I was just silently not sending or receiving messages for nearly an entire day. I had to disable RCS on my phone, which created a several day long issue where some chats would just fall back to SMS and others absolutely refused to work, or strange interactions with Apple devices where certain messages would not be displayed. After enough trouble with it I convinced everyone to switch to a third party messaging app. I'll never turn RCS on again, I can't trust that it won't just start silently failing.

It's a bandaid over iMessage's dominance among iOS users.

RCS allows higher resolution pictures than MMS.

From [0], it seems that RCS can use the cellular signal instead of LTE or 5G:

> In cases where RCS is able to operate over cellular networks without data, it supports messaging as well as file transfer, enriched calling, and more.

[0]: https://en.wikipedia.org/wiki/Rich_Communication_Services

The point of the exercise is for Google and Apple to maintain control over the ecosystem.

RCS is technically superior (protocol, transport, security, all of it) but is captured from the start on the technical level by design by the big players. From the perspective of the vast majority of users who have very limited technical awareness, it was silently slipped in as an upgrade at one point or another. This means that those not adopting the proprietary BigTech solution are perceived as being difficult by insisting on using software that's now perceived as outdated or as otherwise mildly incompatible.