There’s cultural aspects to it. Europe, Middle East and Asia has a culture where there’s enough people up and about till late. People anre anre outside, often at third places like coffee shops that allow you to spend time without spending a ton. Even if you’re at home, you are not in bed at 9, like majority of Americans. I would assume the clientele at the Yemeni shops comes from a place that has the “stay out till late” culture.