Laptops have a screen and a keyboard. Only the screen is needed for consumption and the keyboard gets in the way in several environments, for example a bed. It's both the extra space and the screen orientations that it forces. When all we had were laptops they were great, then we had tablets and laptops didn't look so great anymore for some purposes.
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.
