1080p is a higher bandwidth connection from the frame buffer to the TV than 1080i. However the frame buffer itself is identical. 1080p will look better than 1080i—interlaced flicker is not a good thing—but it makes precisely zero difference to the game developer. Just as most Xbox 1 games let users choose 480i or 480p, because it was no extra work, 1080p versus 1080i is no extra work. It’s just different settings on the display chip.
Inevitably somebody will ask about field rendering. Since interlaced formats display the even lines on one refresh pass and then the odd lines on the next refresh pass, can’t games just render half of the lines each time? Probably not, and even if you could you wouldn’t want to. You probably can’t do field rendering because it requires that you maintain a rock solid 60 fps. If you ever miss a frame it will look horrible, as the odd lines are displayed in place of the even, or vice-versa. This is a significant challenge when rendering extremely complex worlds with over 1 million pixels per field (2 million pixels per frame) and is probably not worth it. And, even if you can, you shouldn’t. The biggest problem with interlaced is flicker, and field rendering makes it worse, because it disables the ‘flicker fixer’ hardware that intelligently blends adjacent lines. Field rendering has been done in the past, but it was always a compromise solution.
