If anything it promotes centralization. Steam is a one stop shop for buying games that you can access globally, for the most part.
Before if you wanted to buy games you had to show up in person, so competition between corporations and mom and pops was limited to what a corporation was willing to spend on capex and staff for a new store. The internet destroyed that need and so now the costs of corporations to compete with more efficient services due to economies of scale is very low.
Before if you wanted to buy games you had to show up in person, so competition between corporations and mom and pops was limited to what a corporation was willing to spend on capex and staff for a new store. The internet destroyed that need and so now the costs of corporations to compete with more efficient services due to economies of scale is very low.