Not just Vienna but many places have great tap water, much better than what you get in a lot of bottles.
There are obviously also places where the tap water is of a worse quality or just tastes awful.
(The problem for many Europeans is that they like fizzy water. It’s possible to add CO2 to your own tap water but bottled fizzy water is just do damn convenient compared to that. I would never buy plain water in bottles but I’m too lazy to not buy fizzy bottled water.)
There are obviously also places where the tap water is of a worse quality or just tastes awful.
(The problem for many Europeans is that they like fizzy water. It’s possible to add CO2 to your own tap water but bottled fizzy water is just do damn convenient compared to that. I would never buy plain water in bottles but I’m too lazy to not buy fizzy bottled water.)