Just hang it up! We aren't talking about anti-cheat software, nor marketing trackers. If we were, the vast majority of programs, including one's OS and browsers are guilty. We are talking about viruses and trojans that can infect one's machine.
The fact is, reputable sites like Steam or GoG just do not contain these things except in very rare instances. You are acting as if they are all over the place and they just aren't.
Can it happen, sure. It just doesn't except rarely. And this has historically proven to be true.
If you are going to be worried about needles in a haystack, you better stay home. Don't drive, don't fly, because rarely people die in car and planes crashes. If you want to live in bubble wrap, go ahead, but to spread your ill-conceived paranoia to others is just not healthy for you or for them.
No one said to just ignore warnings from one's AV. People here suggested to look into it further. Test it on VirusTotal, do a little research and come to an informed conclusion. And after people did their research, the conclusion was that the program was very likely to be safe for all the reasons already discussed in this thread.
But you want to drone on about your doom and gloom. People listening to you should just throw their computers away, because they never know when a virus is going to trash it...all for something that almost never happens.