Question

what is a wholesale trader necessary

Answer 1

It is necessary for common people or business man because it sells at lower prices and not at fixed price or marked price.

Answer 2

if proper storage facility is available ,a wholesaler can supply certain goods during off season too, when it is likely that the goods are not available in the market .fir example ,in large shops
consumer can buy Wollen garments. even un summer.
wholesaler get feedback from the shopkeeper about the choice and preference of the consumer , and pass on the information to the manufacturer.for example ,if there is demand from the buyer for a particular kind of dress material ,the wholesaler will urge the manufacturer to produce that dress material in larger quantities.
wholesaler can also help in avoiding scarcity of food items in emergency situation such as floods or a transport strike.