Juice is not the same as whole fruit
Fruit juice delivers free sugars more quickly and with less fibre than whole fruit. That makes quantity relevant when considering sugar and fructose exposure.
No need to fear an orange
This is not an argument to avoid whole fruit. The useful distinction is between ordinary fruit intake and large amounts of sugary drinks or juice.
Use water for routine hydration
Juice can be enjoyed in moderation, but it need not be the main way you hydrate.