Why does Spotify Ad Analytics recommend a javascript pixel instead of an image pixel?

JavaScript pixel implementation is required get the best details to paint the most realistic story of attributed events.  In the event an image pixel is used instead of a JS pixel, the following limitations apply: 

• No access to Spotify Ad Analytics debugger
• No landing URL detection
• Inability to capture 100% of attributed visitors, because there is no first-party cookie dropped 
• Inability to deduplicate multiple actions from the same user, meaning some of the events may be artificially inflated