DSLR vs. iPhone is apples and oranges. Two devices with completely different use cases.

If your primary goal is to buy a no-compromise device for photography, obviously you should get a full size camera.

But 99% of the time, you're going to have an iPhone in your pocket and no camera on hand. That's why it's great to have an excellent camera in your phone. You can always augment with a DSLR for special occasions, but it's not like a DSLR and iPhone are interchangeable.