Non-alcoholic beer may actually contain alcohol

Keep in mind that water and ethanol are miscible, so it will be very difficult getting the last bit of ethanol out of a mixture. Don't think they're going to do pharma-grade separations to get < 0.5% alcohol out. Similarly, 200 proof ethanol (pure) only lasts until you break the seal. It'll drop to 195 proof from the humidity in the air.

There are different kinds of NA beer. Some are 100% alcohol free. Some are <0.5% which is sometimes called "Near Beer." Then you have small beers up to 2%.

In the case of near beers you usually get more alcohol from eating bread or other fermented products. Small beers can be a little intoxicating if you drink 4x as much as a normal beer. Usually they are so expensive they are pretty much a treat.

All NA beers I've seen prominently point out that they are 0.5% or less in ABV.

That said, AB InBev owns the IP for actual 0.0% beer and all of it's products are fairly good.

Their NA Stella and Budweiser tastes exactly like the original.

Suntory All-Free is a favorite