And of course there's no encryption standard.
But yes, the lack of encryption (outside of Google's tacked on version) is a problem.
Maybe its your phone going overseas and not working correctly.
I buy an Esim for countries I visit, usually before I go. Add it before the flight, sometimes in the country.
List of countries I have worked with: Singapore (Roaming), Indonesia, Malaysia (I may have been roaming in Malaysia) I can't find the esim info, Thailand, Australia, New Zealand, India (Maybe i was roaming, can't remember).
Or more specifically: it's a different product ("Google Messages") that just happens to be based on RCS.
They do have some partnerships with hardware manufacturers that ship Play on their devices, and they will preload Google Messages in there as well.
In essence, it doesn't exist in AOSP, and doesn't really live side-by-side with a normal messaging app (i.e. one that only does baseband native messaging), I wouldn't be surprised if the partnerships and preloading conditions state the manufacturer can't ship their own version (I think at least Samsung had to drop their own "Samsung Messages" app as reported in one of the reviews of a foldable display phone).
In a way, RCS made no difference, and whatever Google did was mostly just to compete with Meta (both FB Messenger and WhatsApp). Fun fact: Google Messages is closer to Matrix than it is to iMessage in terms of comparable technical features.
Thankfully we have Signal, which solves the problem better than either platform option.
I have almost no way to convince anyone other than people very close to me to use it due to the (lack) of network effect. If they could just use it instead of the default messenger then it's a dramatically easier sell.
Obviously it's up to the Signal Foundation about the direction they take but I don't know if I've seen anyone agree with the justifications.
Google and Apple wrap up their locked down BS with SMS for the same reason. It's by default free of network effect but passively pulls people in.
Who sets the MMS limits? the telcos - actually min(both ends), the iPhone sender's telco and the recipient's telco.
iMessage was introduced in 2011. see https://en.wikipedia.org/wiki/IMessage
Google announced RCS support for Google Messages in 2019. from https://en.wikipedia.org/wiki/Rich_Communication_Services
"In June 2019, Google announced that it would begin to deploy RCS on an opt-in basis via the Messages app, with service compliant with the Universal Profile and hosted by Google (i.e. Jibe) rather than the user's carrier, if the carrier does not provide RCS."
Before 2019, Android users depended on their telco to support RCS. The RCS wikipedia article talks about Samsung support for RCS in USA in 2015 and Android Lollipop OS users getting RCS support - but they still needed telco support.Yes Apple provided an improved messaging service before there was one via iMessage, however they have failed in allowing their service to integrate with the rest of the industry that is looking to support an improved open standard that would allow for a better experience between different mobile operating systems.
The original point you commented on was about Apple not integrating with other platforms.
As I said, I'm an Apple guy but Apple should've implemented RCS as soon as the telco's supported it.
My Telco, the largest national mobile carrier, still does not support RCS in 2025, which makes RCS and which mobile platform supports it and which does not a moot point for me.
Telcos do not have an incentive to upgrade the messaging infrastructure alone unless the upgrade comes as part of the core network upgrade, which is usually bound to the number increase in <whatever>G. Since the introduction of 4G, when mobile networks turned into dumb data pipes for everything, including voice, there is very little money to be made in the telco business. ISP's have suffered the same fate.
Android implemented RCS and Apple dragged their feet in implementing the standardised platform such that high quality messaging was seamless and agnostic between brands
The iPhone needed to reduce the quality of pics/videos to non-iMessage recipients because Apple didn't support any other form of non-iMessage messaging.