The Guardian is a paper based in Manchester, England. Fairly certain that they do not mean "liberal" in the American sense meaning left-wing, progressive politics. They mean it in the classical sense meaning free.
I agree with you in principle. As someone who stopped drinking, it would be great if I were paying a buck or two less for that mocktail or bottle of O'Douls.
But it's a matter of scale, right? Both large brewers and soft drink makers have distilleries/bottling factories that dwarf anything an NA product (especially NA spirit makers) can produce. Even Heineken or Guinness with their Zero beers are only dedicating a small portion of their facilities to make it.