What look do you want to achieve? You don't have to have anything, but a headboard does provide a design element.

It's definitely not a MUST to have a headboard, here is an ideabook with alternative headboard designs.

https://www.houzz.com/magazine/headboard-alternatives-to-make-a-dull-bed-divine-stsetivw-vs~18872201

A headboard (or other decorative element, such as Dytecture suggests) will prevent greasy spots on the wall where your pillows touch the walls. Sounds gross, but that's what we found when we bought our house, where the previous owner didn't have a headboard. We painted that bedroom right away!

All good ideas. I use tons of pillows, which i remove for sleeping. Our bed is opposite the fireplace so i might consider tying these elements together. Thanks.

I second the oily walls. Our guest bedroom had no headboard for the first 8 years. When I removed the bed to paint, the wall was a half circle of oil soaked into the paint! Yuk! Now I have a beautiful iron bed, headboard and footboard.