I worked at an Arby’s back in high school (over 20 years ago). They told me free refills were a thing because most customers don’t refill more than once, if at all. Also, the soda water costs pennies and the bags of concentrated soda syrup were only like $10 (at the time). A single bag of syrup, mixed with soda water, could fill customer’s soda cups for maybe 2-3 days before it needed to be replaced. Fast food restaurants make insane profits on soda, so they don’t care if customers refilled multiple times during their visit.
When I lived in Germany for a couple years, I was surprised to learn that the large church in the center on my village was about 1,000 years old. This one building has been standing longer than America has been a country. Over 4x as long, too! European culture amazes me because there’s such a lengthy history, and so many things are much older than I’d imagine. American history is so short in comparison, and we’re more likely to tear down and build new and cheap than create a solid structure that will last for hundreds of years.