A lot of the things mentioned here are enjoyable, (caffeine, sugar, social media and yes, masturbation), but most people are not addicted to them. They simply do a cost-benefit analysis. Take smoking. I used to smoke 3 packs a day and it was very enjoyable, but the risk of getting a serious illness (or giving one to someone else) outweighed the attraction, so I stopped. Across the US smoking rates declined massively over the last few decades, so it seems many others had the same idea as me. I would do the same if anything I really enjoyed turned out likely to do me great harm.

Now I drink coffee every single day. I eat lots of sugar, (but I also do bucketloads of exercise.. I run 50 miles a week for instance). So the probability of harm is small. I also drink a beer or two most days. Sometimes for work I have to travel to remote camps and spend a couple of weeks without a drink. Doesn't bother me. But I do enjoy the first beer when I return home just that little bit more.