Why should they? I honestly think they would have been justified giving RCS the middle finger indefinitely. It's effectively google-owned and a shitty protocol (no e2e by default being top of mind).
Also, the idea of wanting the carriers more involved in messaging is hilarious, just use one of the 10+ 100x better messaging platforms. The carries horribly bungled SMS/MMS and they ceded all control of RCS to google, why in the world would anyone want them involved. They barely can do their jobs as dumb pipes.
By spec E2EE (via MLS, or something extremely similar) is in fact the default - it's part of the Universal Profile, at least as of 3.0 which I have been reading.
Is Google following that with Google Messages? We have no way to verify! How great for everyone.
And this is what I find so galling, it took them to version 3.0 to decide to do that?
My quick googling shows:
v1: 2016
v2: 2017
v3: 2025
So, yes "by default" in the current year it supports it but no one (including google) is using 3.0 yet. Apple has pledged to do it in iOS 26 (currently using 2.4) and Google has some proprietary e2ee on top of 2.6.
It's just all a mess, the furthest thing possible from an "open standard" (not saying anyone claimed it was, that's just what I would have prefered if we were trying to replace SMS/MMS), and hopelessly behind all other messaging platforms.
I was curious about the adoption timeline actually, yeah - hadn't looked at that in detail yet. Thanks!
How wonderful that they've been claiming better security all along too. (it may be true, sms is terrible - but they know many people will think E2EE or similar when they hear that)
I believe they can't. RCS is implemented over IMS (IP Multimedia Subsystem), part of the mobile carrier infra and tightly tied to them (SIM card auth, APN settings pushed from the operator, etc)
That skips the carrier nonsense, and it also means that for iPhone users they're not actually running on google jibe servers.
Thing is. Apple won't do this. Malicious compliance and all.