Yeah... especially since the source isn't really cheap either. Also, I have never understood how it can possibly make sense to ship water from Fiji to the US, or even from France or Italy to Germany. Local mineral waters may not have as much prestige, but they taste just as good. Actually, that would be a better project: compare the mineral composition of mineral waters to check which local mineral water best matches the taste of an imported brand.
It's because restaurants make the most money on drinks, so selling you overpriced water with artificial branding becomes an excuse to charge the same money for water as one would for sodas.
And some cannot be convinced that tap water could be safe to drink. I know a few people who exclusively drink glass-bottled water, because they fear microplastics on top of that.