The problem isn’t even that we can’t buy in any store we want. Thats normal. The problem is that they’re paying to prevent it from being added to other stores, because they know other stores would out-compete them. Imagine how absurd and anti-consumer it would be if Pizza Pizza could pay a peperoni producer to not sell to other pizza chains, for example.
That said, Epic did effectively fund the game from scratch, which makes this more grey area in terms of overall results, but considering Epic’s history, I can see easily why people are viewing this pessimistically.