It does. This article is about Latino workers but there are well known hotspots for CKDu in Sri Lanka and India. There’s other reports of it in the rest of Asia, Middle East, and Africa but its not as well known of an issue and under reported.
It’s in loads of things. Peanuts, spinach, beans, chocolate, avocados, corn, soy… the list is endless. If someone is really sensitive, they can have problems with high oxalate foods. Some people seem to accumulate oxalates, meaning their problems compound, where others have no problem at all. Biology is weird.
Spinach is very high per serving, but all sorts of foods can have high oxalates per serving. Sweet potato, Swiss chard, almonds, beets, chocolate. You'd have to consult the content per serving for all foods you consume if you're trying to avoid them.