Very few people have absolute 0 willpower.
Excepting those with a medical condition, low willpower individuals can invest that willpower in developing more willpower and get to average levels over time.
I've seen this many times working with the homeless and in addiction recovery. It's just like compound interest with investing.
Just because you start with a very very small amount doesn't mean it can't grow over time.
This is embarrassing as hell to admit, but in high school my ADHD was so bad the only thing I enjoyed was World of Warcraft. I would commonly play for more than 24 hours and couldn't get myself to stop for anything. It completely dominated and ruined my life. You can say video game addiction isn't a thing if you want, but I was definitely acting like it was. Tried alcohol, cocaine, etc.. and never had a problem, but I could not control myself with certain video games.
When I started developing my Willpower it was literally with 5 minute breaks every 4 hours. And it was extremely difficult. After a week, I extended those to 15 minute breaks, and it was 6 months before I got my total WOW time to less than 8 hours in a day. But I did it.
I'm in my 30's now, and this new World of Warcraft expansion is the only one I haven't played at all. Hoping to keep it that way.