As much as Steam is free to host what it likes, Visa and the others are free not to work with Steam. You could argue the options available to Steam would be significantly limited by that, but the same argument is being used against Steam now in the Wolfire lawsuit. The argument is that Steam violates antitrust law via illegal tying and other means, making it hard for a user who doesn’t agree with their content policies to switch to a different platform, like Epic, which has always prohibited porn games.

Well, some people do want that.

There should be a separate platform for that, similar to how you wouldn’t go on YouTube expecting to see videos from PornHub.