Hopefully this even frees them to do things we've wanted for a long time... like not being tied to a phone number and offering better features than RCS/iMessage. Maybe even having multiple independent profiles/pseudonyms for compartmentalization.

That's how Signal could be growing the base and interop with SMS/MMS/RCS cruft on one platform will always lack the killer feature and be irrelevant to the other platforms. If Signal were better than SMS/RCS/iMessage people will just use it for those reasons in addition to the security and privacy.

And having just installed the beta and used the SMS export and allowed it to purge all of SMS content from Signal into Google Messages it actually sort of is nice that the app is now ONLY the "Signal" context. I'm... actually pretty okay with SMS belonging to the "Stuff that Creepy Companies Like Google Know" context.

Basically this just does what Signal already does in iOS: it must compete with the native messaging client. Google is already playing RCS as SMS upgrade and Signal is making the correct strategic decision to not make a play for RCS. SMS support is just going to lead to whining about lack of RCS. The bottom line is both Apple and Google are out to kill SMS. With SMS gone, Signal can just move on to feature parity with iMessage and beyond while leapfrogging whatever messaging clusterfuck Google keeps producing. Google can have SMS for all I care. We can't have iMessage on Android, but we can have Signal on both Android and iOS.