Why did exploers need more accurate maps?

So when the looked at the height of the north star or the sun they could figure out there coordinates more accurately. This would map a map more useful.

Most earlier maps that included the region were not intended for navigation and were so imprecise that they are virtually unrecognizable to the modern eye.

With this map, it’s as if some medieval mapmaker flew to the heavens and sketched what he saw - though in reality, he could never have traveled higher than a church tower.