Juices are just the flavor and liquid from the fruit, not the fiber and other benefits of eating the whole fruit.
The only source of sweetener found in nature is honey, and even that is self limiting in how much you can consume.
Everything we have as a sweetener must be refined to get it.
Our bodies just were not created to eat sugar in the amounts that juices and sweetened drinks contain and not made to have it hit our bloodstream that fast.
Fructose/glucose....fructose fructose....fructose plus glucose...decisions decisions.