First, some local shops do start the whole process with cocoa be

Second, you are right that most shops use 已经制好的巧克力块. The differences are they are made of different batches of beans. Some batches are simply better than others. It is the same as those in wine- and beer-making. For example, the grapes from the same wineyard are much better in some years than other years. It is determined by weather. This applies to chocolate making as well. Excellent shops are very picky on their beans and chocolates. They would pay higher price for them. That is one of the reasons that their final products are pricier. This won't apply for big manufacturers.

As for the winners in free market, I think they are different things. The winners must have good products. Otherwise, they won't win the customers. But that doesn't mean they have the best products. I will stop here since we are talking about food, not economics, which is a much larger topic :)