A company as big as Amazon exists across thousands of communities, and in contexts that don't even include communities. It can afford to harm some contexts while profiting on others, because it is a monolith. That's why when we talk about business law we need to consider more than just the simple economics, because companies can have greater impacts than that.
Anti-competitive laws are just that, they're not about increasing simple metrics, they're about managing the harder to measure externalities of bigger companies like the ability for a market to be competitive, promote innovation, and to make sure customers have enough choice to choose with their wallet.
I'd say they make it easier to make mistakes in reasoning. Just as unilaterally deciding what "we're" talking about is also a mistake.
Positing that Amazon is too big to buy a computer game company is just wrong. This in no way creates a monopoly on computer game creation, which is one of the best industries on the planet in terms of lack of lock-in in the forms of regulation, machinery, or IP law. Have computer, download Godot, get going.
Also, Amazon is a silly company to level that charge at. They in no way control a significant amount of the game creation industry. You may be thinking of Microsoft.