Why is sushi junk food?

Could you elaborate on the claim that sushi is considered junk food? It's often perceived as a healthy meal option, featuring raw fish and vegetables wrapped in seaweed or rice. Are there specific ingredients or preparation methods that make sushi comparable to traditional junk food, such as high levels of sodium, preservatives, or unhealthy fats? Or is this a cultural or regional perception that may not apply universally? Clarifying these points would help understand the basis for this assertion.