So an apple contains about half the sugar a can of coca cola does, and comes with various other benefits?
You’re unlikely to eat two apples in a row, let alone eight or nine on top of having all three of your usual meals. But you could fairly easily drink an entire large bottle of coke throughout the day, which is exactly the problem.

Edit to add: this is why fruit juice isn’t exactly healthy either. Sure, it’s got vitamins, but it’s basically soda.