Fruit juice naturally has around 0.5% alcohol. It's just a side effect of wet sugar.

There's no legal federal limit, it's all state law. Some states go by that 0.5%. others go by a definition that includes "things sold as beer" essentially.
"You are holding a container. It is labeled beer. Do not give it to anyone under 21.”

Other times stores just assume and card everyone because it's waaay easier than nuance and you're not legally required to sell non-alcoholic beverages to minors.

They say “contains less than 0.5%” because that’s the cutoff that makes something legally beer. It more than likely has none, much of the time. That’s just the law (US):

> 0.5% it’s beer and subject to alcohol laws

< 0.5% it’s not beer, technically a soda or something

So they label it as <0.5% simply to show that it’s in the latter category. This creates a lot of confusion for some reason.

Even the grocers (and even manufacturers) get it all messed up. Hell, half the brands don’t have required nutritional info (beer doesn’t need it, soda does) but the real problem is that:

The regulatory agencies are captured and don’t do shit anymore. TECHNICALLY the FDA should be stepping in and making them put full nutritional information on all the brands of NA “beer” and making sure it is labeled and sold like a soda.

But the larger companies that sell it are just misclassifying it and creating problems to be as lazy and risk avoidant as possible.

Another counter example that disproves the misunderstanding is kombucha. Kombucha has naturally occurring alcohol, but it’s not classified as some other category. The legal categories are “Alcoholic beverage” Or “Not alcoholic beverage” and it’s less than 0.5% so it’s “not alcoholic beverage” and therefore is available for anyone to buy and has nutritional information on the container.

Similarly, NA “beer” should have the full nutritional information on the can and be sold to anyone. It just “feels” like it should be different somehow, and no one is updating or enforcing policies. You might notice that none of them actually say, “beer.”

Apple juice can contain around 0.5% alcohol though?

They say “contains less than 0.5%” because that’s the cutoff that makes something legally beer. It more than likely has none, much of the time. That’s just the law (US):

0.5% it’s beer and subject to laws < 0.5% it’s not beer, technically a soda or something

So they label it as <0.5% simply to show that it’s in the latter category

But the grocers just do whatever. Hell, half the brands don’t have required nutritional info (beer doesn’t need it, soda does) but the real problem is that:

The regulatory agencies are captured and don’t do shit anymore. TECHNICALLY the FDA should be stepping in and making them put full nutritional information on all the brands of NA “beer” and making sure it is labeled and sold like a soda.

But the larger companies that sell it are just misclassifying it and creating problems to be as lazy and risk avoidant as possible.

The 0.0% on the poster must legally be without alcohol whatsoever. What you have in mind is a confusingly named non-alcoholic beer which goes under the official alcoholic beer radar.

That will have been because whoever shelved it didn't know what it was.

We can also buy 0.5% shandy at any age.

Yup. I got carded at Home Depot when buying a saw blade because "it could be used as a weapon".