Steam was around for long enough, with it’s array of features, that I have grown accustomed to having them. Even when it first launched, Steam was more than just a store and library.

Even as just a store and ignoring all the other periphery features, it has more features for actually finding things than any other digital market for buying games. Not to mention sales, user reviews, and more.

Steam is widely regarded as the best option because they do things in the interest of their customers, instead of shareholders with a stake in the company.