In Sweden zero sugar has become the default, if you go to like a McDonald’s or something and only 1 option of for example Coca Cola is available it’s going to be zero. In stores the zero is placed as like the ”main” option and is most accessible and if you’re willing to a dig into the aisle a bit you might find it with regular sugar as well.
Having visited many other countries, cola zero is often available but many times other flavors are not guaranteed to have a zero sugar option.