so okay the first 5 is irrelevant (right?), so it's a "near monopoly", one actor dictates the prices
but it's ea and the like floating 100$ games, valve is just taking their 30% cut of whatever people ask, and do their own thing. other platforms can do what they want on their own platform, as long as they're not selling steam keys.
i'm not buying the "market is controlled by steam" argument
i get that as a dev, if you want the best exposure on pc, your only realistic choice is to sell on steam, because it's so popular, but many people start out on itch, and when they get big enough, launch on steam. and they're still on itch too.