They spend 1,000 times more than you to build out a network. 30% is lower than what Walmart would charge you if you were lucky enough to get listed. Most people raise prices to cover these and advertising costs. If you tried to replicate that network the time/effort would outweigh the costs.

Spending years on an indie game was never going to be that profitable. I hope you build the game for other reasons aside from profits.

err.. no they don't. An indie publisher is typically one or two marketing dudes sitting in an office somewhere and pretty good at writing press releases. Walmart is a massive retail chain with.. like.. millions of employees and like.. thousands of brick and mortar stores.

Oh, perhaps you thought I was talking about the platforms like Apple, Google, Steam and the like. I don't begrudge them their 30%