More than 160 characters in a text. Hi-res images and videos. Sent/read receipts. Group chat features. Location sharing. Video calls. Sender verification. Blocklists.

Pretty sure all of this qualifies as "more interoperable".

Those are more features, which is nice but has nothing to do with interoperability. The set of people you can talk to before and after Apple implements RCS is the same.

If you define "talk to" as being able to share 160 characters of ASCII text then sure, but today messaging means a lot more to people than just that.

Yeah, and the internet is just sending 1500 bytes of binary data. There are no phones that actually cut you off at 160 characters, it's an implementation detail at this point. And MMS is fine, not great but fine.

But regardless, let's push the goalposts back, the whole point of interoperability is to allow people on different messaging networks to communicate. The users of RCS is a subset of SMS.

Your arguments would be a lot stronger if you focused on the SMS limitations that have not already been alleviated by MMS.