How come skin cancer doesn't spread as easily to other organs as compared to other cancers?

It can: It depends on the type. Melanoma spreads to many other sites, and can do so very quickly. Basal cell and others tend to spread slowly. Regardless, cancer of any type, should be monitored closely, and treated promptly.

Depth of invasion: Unlike other skin cancers such as basal cell or squamous cell, a melanoma can spread to many organ quite easily it has something to do with how easy the cancer cells go to lymphatic organs ( lymph gland) or blood vessels to spread and how fast the cancer grows. The depth of penetration/invasion of the cancer is very important for the skin cancer to spread.

It can: Melanoma can travel to any organ in the body.