Mostly the water is more or less safe but chlorine is added in many countries. That won't kill you but it's not very nice. And those big containers of water are

Mostly the water is more or less safe but chlorine is added in many countries. That won't kill you but it's not very nice. And those big containers of water are affordable enough that they are preferable for cooking/drinking. I'm currently staying in Portugal and I'm buying a lot more water than I normally do. Back in Germany, the tap water is fine. But I do buy a lot of sparkling water because I like drinking it. Also, my urologist mentioned that bottled/filtered water is a great way to reduce the chance of kidney stones. The same calcium deposits that eventually destroy your washing machine might cause you some issues with those. So, there's that.