Drinking five diet Cokes a day is probably healthier than drinking 5 regular cokes a day. Sugar is linked to diabetes and other ailments.
[1] - https://en.wikipedia.org/wiki/Aspartame_controversy
[2] - https://www.smh.com.au/technology/sydney-university-study-cl...
Plus, it just tastes worse. I'd much rather have a single sugar-containing soda on the weekend, or after finishing some hard physical labor, than liters of diet soda every day.