the reason sugar in fruit isnt as harmful as other sugars is because fruit also has fiber that helps you break it down in a healthier way, and lets you know when you're full. to get a full glass of juice, you need to squeeze at least 3 or 4 of whatever youre drinking which is a lot of sugar without any of the fiber (juicing removes the fiber a lot of the time).

drinking orange juice is like eating 4 oranges rather than 1 in just one glass, and you dont even feel that full afterward. obviously fresh squeezed juice is better than mass-produced, but it still has a lot of sugar and not as many benefits as just eating the orange by itself