They have a functional monopoly on game launchers, but it isn’t illegal to have a monopoly — it’s only illegal to use that monopoly for anti-competitive actions.

A monopoly in law doesn’t mean total (100%) market control; it means having the power to control prices or exclude competition. Courts often refer to this as monopoly power.

A monopoly could exist with as little as 50% of the market, or even lower. Steam has around 70–80%, which is easily enough to be considered a monopoly. However, you could argue that despite their large market share, they can’t truly control the market, since it’s their goodwill and consumer-friendly behavior that earned them that share in the first place — and if they ever tried to abuse it, people might go elsewhere.

Personally, I don’t really believe that. Considering your entire library is tied to their platform, they could pull all kinds of shady tactics if they wanted to. But it’s an argument.

As far as I’m concerned, Steam is the least evil of the major corporations. I can overlook the secret gambling ring and possible dark-money smuggling complicity because they seem to be a net benefit to consumers, and the harm mostly falls on those complicit in the scheme — as well as on China and Russia.

Edit, fixed spelling.