They’re relatively cheap and provide a lot of nutritional value for the weight - I buy them in big bags straight from the farmer’s market. Tree nuts (peanuts aren’t actually nuts at all - they’re legumes) are literally a luxury only the rich can afford in my country these days - kind of ironic since we’re the world’s top producer of macademia nuts.
Roasting them is actually important since that degrades aflatoxins - they also just taste better.