Ok, I did the digging on this because you asked. I actually just assumed because I was carded for NA beer that this was a law.
In the US, federally it is not illegal to sell less than 0.5% without carding. But many states treat NA beer the same as normal beer and they require the person be over 21. In the states that do not require 21 and over for NA beer many (most) stores and bars will still card because its better safe than sorry when it comes to ABC and losing your license.
postmateDumbass@lemmy.world 14 hours ago
Rates of alcohol use and addiction have been decreasing.
This is just getting them started early like cigarettes always tried to do.