Yeah, "everyone" knows that. Except the world har an incredible amount of people who fall for these kinds of scams. And there are less obvious scams around.

I almost fell for a strange scam a while ago. A Steam user by the same name as one of my existing steam friends added me. I assumed it was his second account and accepted. A few days later, he messages me, asking me to participate in a DOTA2 tournament. I had previously played DOTA2 with this person, he spoke to me in our shared native language which is not English and everything seemed in order. I said I haven't played DOTA2 in years so I'm beyond rusty, he said I don't have to play, they just need me to register so they have a full team for the signups and then they'll find someone else to play before the tournament starts. Sent me a link to a website requiring a signup and I can't remember what it was now but there was something about the signup that irked me. Maybe it was just creating a account, maybe it required a credit card or something I can't remember but I ended up looking at my steam friends list and noticed both the accounts were online. So I sent a message to the other account asking if this is them, he said no and then I noticed the same scammer had added another mutual friend so I messaged them too warning them about it.

That's the closest I've been to getting scammed that I can recall. I'm not sure what the scammer would gain from my signing up but I'm sure they had some kind of profit angle.

And yet people still do it.