Why was finding new trades important to european leaders and early explorers?

It was important because the Europeans. And early explorers needed better weapons, food and cloths and so they could trade for more useful stuff.

herodotus taught this. herodotus was an ancient greek historian who was born in halicarnassus in the persian empire. he is known for having written the book the histories, a detailed record of his "inquiry" on the origins of the greco-persian wars.