Except the core premise is not true, so far as I can tell. To confirm this I went on Uber Eats, looked for chain restaurants near Salesforce Tower, and surveyed their beverage menus. At initial glance, most restaurants charged more for "water" than for soda. However, on further inspection this is because in those cases, the soda was dispensed from a fountain and the water was bottled. The latter obviously would cost more than the former, because of the cost of having to transport individual bottles. This can hardly be attributed to "Capitalism truly sucks". Furthermore, in cases where a soda fountain is available, the restaurant is legally mandated to provide the water to you for free[1], which makes the cost of water in those places $0. Of the places that only sell bottled beverages (there's surprisingly few):
* California Pizza Kitchen charges the same for water as for canned soda, and gives you more water[2]
* Chipotle Mexican Grill's cheapest beverage is bottled water[3]. The second cheapest option? San Pellegrino sparkling water, shipped all the way to California from Italy.
That said, the economic principle of "thing x costs more because people are willing to pay for it" is probably true (see for instance, airfare that's bought late), but this isn't one of those cases.
[1] All restaurants are technically supposed to, but having a soda fountain virtually guarantees that they can't weasel out of it by saying that they only serve bottled beverages and don't have cups for serving tap water
[2] https://www.ubereats.com/store/california-pizza-kitchen-53-t...
[3] https://www.ubereats.com/store/chipotle-mexican-grill-211-su...