I don't think this is really comparable at all. Sony is trying to kill off the used game market in hope of being able to coerce people into paying more. Steam is basically one giant used game market in that you get stuff constantly for 50-90% off.

And pirating stuff off Steam is generally extremely trivial, so it's a largely coercion-free business-customer relationship, and I think that's a large part of why they're doing so well. People like to support businesses that treat them well. And for those that don't? Well I think there's a reason that video game piracy is plummeting, while film/media/streaming piracy is surging.