Why doesn’t my smartphone integrate with my tablet?

A tablet seems like a natural extension for my phone. When I’ve got it with me, and I’m actively using it, it makes much more sense to use it to interact with my phone, so why can’t I? Incoming calls should pop up on my tablet, as should incoming text messages, Facebook Messages and the rest. I should never have to pull out your phone if the tablet screen is powered on and active.

More so, what if your phone was the “key” to other devices. You’ve unlocked your phone, and then it tells nearby devices who you are. I can’t stress how much I agree that I shouldn’t have to pull out my phone when I’m using a tablet or PC.