Energy drink is a huge umbrella term that encompasses 16 Oz or larger cans of heavily sweetened liquid, drinks the containe strange stimulants that are way more aggressive than caffeine, workout drinks that have no caffeine, drinks with caffeine and a ton of tangential stuff in it and vitamins, to drinks that have less caffeine then a cup of coffee.

A Venti Starbucks has 5x more caffeine than an 8oz redbull and vastly more sugar, depending on your preferences. A like comparison has 20oz Starbucks at >400mg caffeine and avg of 300 calories (0-600 range, most people choose 400+ options). 20oz of redbull is 171 MG caffeine and 258 calories.

Energy drinks are just easy and more predictable than coffee.