The problem is here they have total monopoly of the High Street having basically killed of everybody else.
If you don't like online shopping and retailers such as Amazon and Shopto you have little choice but to use them.
Yes Supermarkets sell games but there stock is minimal at best and only Games like Cod do they have plenty of stock of.
I have been to a supermarket on many occasions to pick up a AAA game and on a lot of occasions they haven't had it in or they had sold the limited stock.
Game to me are used basically as a trade in post and nothing more.