It's a shame Coca-Cola doesn't have a cheap canned sparkling water
This is not because I am a fan of Coca-Cola.
However, many restaurants and other places beverages are served have a sort of exclusivity agreement which makes it hard when there is not a sparkling water option. I don't know exactly how these work, as there can be exceptions like Dr Pepper, but I think it makes it hard to offer products from a competitor.
They had AHA, which is mostly discontinued (except freestyle machines and some airlines). They had Dasani sparkling water which is also discontinued.
Now they have Topo Chico which is more premium and doesn't compete in the same category as LaCroix, Polar, etc. They also have under this brand a Spindrift type juice mix too, but this is both more expensive and not just a simple sparkling water.
My local Mexican restaurant used to have Topo Chico glass bottles available, but with the shortage hasn't replaced it.
Another restaurant used to have AHA cans, but after AHA stopped being made they stopped having any sparkling water.
Even my office has free Coke products available. We used to have AHA but when AHA was discontinued, they never replaced with another sparkling water option. I have free soda but don't want to drink it.