Why must there be more producers than consumers within an ecosystem ?

Because for example one large eagle needs lots of small sparrows to eat. There is usually a food pyramid so for example you could display it along the lines of 1,000 worms are eaten by 20 sparrows which are eaten by 1 eagle. Its just the way things are. It is a fine balance. if you went up to two eagles on same land they would run out of food quickly and then would either starve or have to move on and using up all the food doesnt help them so it needs to be in a fine balance. A balanced ecosystem.

Because producers are eaten by primary consumers and primary consumers are eaten by secondary consumers and secondary consumers are eaten by tertiary consumers