No, it works because Amsterdam has infrastructure in place to make it work. My "home" town is Bath in England - population of ~90000, and vastly smaller than Amsterdam. However, the transit infrastructure there is terrible. It's also worth noting that Amsterdam has not always been how it is today: in the 70s and 80s it was filled with cars.

The main difference isn’t the size, it’s the layout.

I’m in Berlin (metro area population 6.1 million compared to LA’s 13.1 million) and I don’t need a car or a bike because I have at least 22 food supermarkets (including 3 in a shopping mall), 2 household electronics stores, a building supplies store, a hacker shop, and countless bakeries and spätis [0] within 1.0 miles.

Judging by Google Maps search results, I’d say Amsterdam is similar.

I’ve explored a few American cities on foot, and if those places were representative of the rest, I can understand why Americans would regard cars as mandatory; but the model of large stores, few and far between, is not the only one.

[0] https://en.m.wikipedia.org/wiki/Spätkauf