Uh yea, because we do so much more on our phones, it might be well designed, but it was well designed for the 90s. That's why it makes a good fallback protocol, but by no means should it be the go-to.

RCS is the replacement, it's been the replacement for a long time in the EU. In fact, if the US carriers just implemented it when the EU did, this entire thread wouldn't even exist.

It's a standard until Google takes control of the GSM Association.

Here's a Wikipedia article on RCS : https://en.wikipedia.org/wiki/Rich_Communication_Services

Even has this blurb:

The Verge in 2019 criticized the inconsistent support of RCS in the United States, with carriers not supporting RCS in all markets, not certifying service on all phones, or not yet supporting the Universal Profile. Concerns were shown over Google's decision to run its own RCS service due to the possibility of antitrust scrutiny, but it was acknowledged that Google had to do so in order to bypass the carriers' inconsistent support of RCS, as it wanted to have a service more comparable to Apple's iMessage service available on Android.