Sugar isn’t even a problem if you’re eating a moderate protein, low fat diet and not eating in a surplus or obese. It’s really the combination of the rest of the American diet that makes sugar a huge problem. Sugar in fruit especially is not a problem because the fibres cause it to be digested slowly anyway.

Fruits are good fiber sources.

Juices do not have fiber, just sugar.

Orange juice is not a good source of vitamin C. Neither is any other popular fruit juice. Most fruits are rather poor sources of vitamins, so they should be eaten for enjoyment, not for the hope that they cover your necessities in essential nutrients.

Eating one raw red bell pepper daily would provide an adequate intake of vitamin C. Kiwi fruits are also much better sources of vitamin C than oranges, eating a few provides the recommended daily intake. There are only a few other good choices, which do not require eating great quantities daily, e.g. black currants, broccoli, cauliflower.

However, adding to food pure ascorbic acid powder is about ten times cheaper than ensuring your vitamin C necessities with fruits or vegetables, so based on cost it can be the better choice.

The vitamin C supplements in pills or capsules are typically very overpriced in comparison with pure ascorbic acid powder and they mix the useful vitamin C with garbage excipients. Using ascorbic acid powder like table salt (but in very small quantities, according to the recommended daily intake), to enhance some of your food, is cheaper and healthier.

Fruits are not the immediate problem. You need 2-3 oranges for a glass of juice that you drink in one sitting.

Try peeling and eating 2-3 oranges in a sitting. It takes much longer and I would argue most people would be fine with eating one orange. But drinking a glass, or even a bottle of orange juice is something that goes much easier and faster.

Also, an orange also has fibre and stuff, so you get more of a healthy package opposed to just the sugar water.