The point is not that you can audit it yourself, it’s that SOMEBODY can audit it and then tell everybody about it. Only a single person needs to find an exploit and tell the community about it for that exploit to get closed.

IDK why, but this had me imagining someone adding malicious code to a project, but then also being highly proactive with commenting his additions for future developers.

“Here we steal the user’s identity and sell it on the black market for a tidy sum. Using these arguments…”

Did you fabricate that CPU? Did you write that compiler? You gotta trust someone at some point. You can either trust someone because you give them money and it’s theoretically not in their interest to screw you (lol) or because they make an effort to be transparent and others (maybe you, maybe not) can verify their claims about what the software is.

I don’t use the term “open source”. I say free software because giving someone else control over your computing is unjust. The proprietor of the program has absolute control over how the program works and you can not change it or use alternative versions of it