You should not need to reverse engineer a piece of software for it to not spy on your network activity. Either way, it's not clear whether resolving cheatsite.com is that well-correlated with cheating. There's a reason why this is called Hacker News.

That's another topic, but that's kind of my point: Valve weren't doing anything akin to kernel-level shenanigans, and even without that, some of the stuff they did already backfired because of privacy concerns.

Since then, they've focused on other avenues to combat cheating (e.g. Overwatch, a replay reviewing system involving the community, or VACnet, a ML model that they trained to recognize in-game behaviours linked to cheating).