I mainly use WhatsApp. I have tried moving on from it, but it is too pervasive in my circles. If I stop using it I will miss too much, so for now I'll stick to it.
I use Discord and Instagram. I hate pretty much everything about the latter but everyone in my friend group uses it. I wish they still had that app with Instagram dms and nothing else.
The confusion around messaging standards, even among the "non-normies" shows they made a good call removing SMS functionality from the app.
An average joe doesn't distinguish between SMS, RCS, iMessage, Signal, Messenger, WhatsApp, Line, Kakaotalk, Instagram chat etc, it's just "texting" to them. People were so confused about all these that even r/signal was full of posts "why does texting to iPhone still suck after installing signal?".
It was a daily thing, for whatever reason users didn't understand that Signal fixed the blurry photos problem between iPhones and Android devices but ONLY when used Signal-to-Signal. Normal SMS/MMS texting was still limited by this technology. Or another thing, people though Signal made chatting free. Sure, if used for sending Signal messages and not SMS. SMS were still within your plan, so why would Signal suddenly make them free?