As others have said, SMS is fully interoperable up to and including groups and MMS.
Your problem comes from that fact that Apple cleverly introduced way more capability in the very same Messages app, for other Apple users only.
None of the complaining like yours would be happening if Messages was left as SMS only and apple had shipped a separate iMessage app, which is exactly what Whatsapp is. But there's Apple's forte. They have Bluetooth, but buying Airpods automagically works better.
I also 1000000% guarantee you that the designers spent a LOT of time analyzing the green bubble colour to make very it a slightly (but not too much) aggravating green. There are many many more pleasant shades of green.
What you want is for Apple to be forced to extend its proprietary system to non-Apple systems, but when you say it like that it's obvious what an unfair nonstarter it is.
Nah, why? Apple has delivered a lot of innovative features through iMessage. SMS texting used to be trash, until Apple iMessage forced them to improve the underlying protocol. It's STILL not as good as iMessage (memojis, extensions and games like Giphy, voice messages, etc)
Paying for SMS messages, when it costs phone companies literally nothing, is what should be illegal.
SMS is still trash compared to WhatsApp or half a dozen other platforms. But SMS is also the only standard we have and, as a standard, usage should be standardized across devices. Apple's manipulation of the standard turns it into proprietary gatekeeping. Why in the world should I know or care if a text I am receiving is coming from an Apple device or an Android device? That's not part of the standard, that's Apple naked attempt to coopt the standard.
Like I said above, iMessage is just a partial WhatsApp clone, but behind a gate. The thing is, for users behind that gate, it coopts SMS too, removing it as the universal standard.
I suppose the same is true on Android if people use their stock messages app? But what drawbacks does it have when messaging an iPhone user? I've never heard of any problems (I don't use that app) but I hear about the differences iPhone users experience all the time.
> But what drawbacks does it have when messaging an iPhone user? I've never heard of any problems (I don't use that app) but I hear about the differences iPhone users experience all the time.
There are no differences with iPhones, other than the green bubbles. On the other hand, Google Messages tags SMS with "Sent as SMS".
The issue is purely based on aesthetics, if anything. Green versus blue bubbles. But there are really no interoperability issues with iMessage handling SMS.