Regardless whether you agree with that, it is super practical for me and my family. It also means we don't have run other chat software like WhatsApp.
The whole experience is just so seamless and well integrated across your devices. Everything from regular messages, voicenotes, sending cute animojis to your wife, or doing a FaceTime with my 102 year old grandmother. I do that on a daily basis. And I can easily continue a conversation from my computer, or even respond from my Apple Watch when exercising.
I am still on WhatsApp though as there are millions of users worldwide, but I keep notifications off and check it only once a day.