

You have no idea if China did that. If they had, they would have taken great efforts to cover it up, and could very well have succeeded. It’s a small wonder we know any of the terrible things they did, such as the genocide they are actively engaging in right now.
I’ve been running steam on an unsupported OS (osx 10.13.6) for almost a year and a half now, and the only issue is a banner at the stop claiming that steam will stop working in 0 days.
I don’t remember what if anything I did to make this happen, but I’ve had no trouble buying, downloading, or playing games in that time.