“Like you said...not all tap water is nice to drink.”
No water – tap or otherwise – is particularly nice to drink. It has no taste (other than that of the various pollutants that are in it) and its only purpose is to slake one’s thirst.
“As I see it, buying small amounts of water is entirely a modern problem, caused by people having more money than sense.”
Mikey is completely correct. Nobody prior to about 1980 was seen guzzling water in the street. With the exception of a very few people whose lifestyles and/or work prevents it or who have a medical condition that requires it, nobody needs to be continually sipping from a plastic bottle every few minutes. Just how long are most people away from a water source that they have to cart bottles of the stuff round with them?
“The only way to obtain clean drinking water is to buy cardboard cartons or glass bottles,…”
And where do you think the “clean drinking water” comes from, NM? Further than that, as soon as the bottle is opened it it comes into contact with air (and everything in it) and some of what’s in it proliferates quite rapidly as the water warms.
The bottled water industry is a triumph of modern marketing - suggesting to people that they must buy something that they don't need and that is scarcely any different from the same stuff they can get from their tap. Good luck to those companies and good luck to the people who fall for their charm.