It doesn’t. Some of the Swiss waters are very good. My baseline for coffee is quality single origin Geisha, and good Swiss water is better than most espresso places.
In the UK I use Redber for beans, I drink decaf (Swiss Water prices) fresh ground in the afternoon and have 2-3 caf cups in the morning. Redber had a wide selection and several roast levels.
No caffeine after noon. I use a 2-cup espresso Bialetti stove top, the second smallest.