Rest of the world is bemused by the stories of bullied US teenagers who don't have 'the right' bubble colour on their SMS-ish app. Elsewhere we've all been using whatsapp/telegram/signal etc for years and we're never going back.
I think maybe the worst decision Apple made was not trying to push out their service (with maybe a few limitations to upsell the hardware) - although I guess blackberry tried to do that and it didn't work out.
I mean, I wouldn't install any FB software on my phone. I'm not sure "we just use WhatsApp" is the flex you think it is.
But the "US teenagers bullied" is one of those BS stories that is blown out of proportion because in a country roughly the size of the EU, you can find a lot of idiots. And US news loves stories about how your children are in some kind of peril - often peer related.
They choose not to deliberately to tie people into iPhones.
Apple does do that.
They provide a toggle (defaults to off) not to fall back to SMS. Which makes sense as an option, because it would suck to send what you think is E2E encrypted and then find out it went in clear text.
If they were first to market with an app for android and ios I feel like things might have gone very differently.
Blackberry blew it by not trying to do that till blackberry was dead. then once the whole world had migrated to a different solution they brought out their messenger. Whatsapp at best was a clone of blackberry messenger.
The time to open up your standard is at the top, not after everyone is / has abandoned you for the "next thing".