They even told me so when I installed it: https://support.steampowered.com/kb_article.php?ref=7849-RAD...
This is not spyware, this is a platform I chose out of trust.
Guild War 2's spyware is exactly that, a spyware. I never agreed to it, or if I did it was out of some legal black pattern.
If you are saying that Steam was very upfront with its anti-cheat measures and that you agreed to it then so be it.
This is one of the multiple reasons I don't mind Steam's scans. They are doing it on the behalf of thousands of games.
When people are worried about their privacy due to the VAC, they are quick to respond. Even better, they don't simply throw a legal team at the community but take the time to address fears and trust issues. [2]
I am not saying that Valve is perfect. They might mess up in the future. But so far, they have yet to breach my trust.
[1] https://partner.steamgames.com/doc/features/anticheat/vac_in...
[2] https://www.reddit.com/r/gaming/comments/1y70ej/valve_vac_an...