If you ask to borrow $500 and I give it to you, and you run off with the money with no intent to ever pay me back, did you commit fraud? Or was I just a rube who should have known better?
You seem to wish to live in a zero trust world model where everyone is out to scam everyone at all times and "caveat emptor" if you do get scammed. We should do our best as a society to not turn into that.