Keyboard can be helpful in consumption scenario, simply because you can set up correct angle for a display. IPad cases I uses typically have just a single position.

That said, iPad is more convenient when in a bed because you can more easily put it away when you get sleepy, you can read sideways, it's more resilient if in a good case, etc. I never carry laptop to bed, while iPad is part of my go-to-sleep routine since v1.