I can only see half of them, but the two negatives talk about dodgy stuff running in the background. Anyone know if Steam has any kind of safeguards against potential malware like this? I feel they must but I couldn't see any official statement.

That’s just FOMO, Fear Of Missing Out, scams rely on manipulating emotions. In this case, I don’t know, I don’t see how emotions are being manipulated in this case, but someone else may.

Most of the ones I've seen are just early access games that will become paid when they do their first proper release. I guess some might be trying something dodgy, but it's not like someone adding a free game to their steam account is being scammed out of anything, right?

There's also an AI disclosure in the description for the in-game assets