What is the point of lugging bottles and crates of mineral water home when you can simply create fizzy drinks without the hassle using so-called “carbonation devices”?

You may want to carbonate your tap water, but this won’t turn it into natural mineral water!
We should not confuse mineral water with straightforward fizzy water. Furthermore, the carbonated tap water is soon flat if it is prepared with “home devices”. If one considers how much it would realistically cost to make carbonated tap water for a household and think in particular in terms of the return on investment and the amount of carbon dioxide that would be needed based on the normal average consumption of a modern family, that ’homemade’ carbonated water would cost approximately twice as much as bottled natural mineral water from the middle price category.
The hygienic safety of the drink produced cannot be guaranteed if the devices are not carefully cleaned and disinfected on a regular basis. Bacteria could be everywhere.
The addition of carbon dioxide to water does not improve its quality. It does not remove chemical residues (taste of chlorine) or eliminate possible pathogenic bacteria. You cannot make a “dubious” water “safer” by adding carbon dioxide.
Source: Verband Schweizerischer Mineralquellen und Soft-Drink-Produzenten (SMS) - [Association of Swiss Mineral Springs and Soft Drink Producers].