investment site are fast scam.. but sometimes investor win.
If it is a HYIP or Ponzi (usually the same thing anyway), the 'investor' only 'wins' by profiting from money stolen from other users.
This is just how any other gambling works too. Most of people lose and house and those who win will get their money.
I think ponzis are scam only if they lie that they invest the money to make the profits or if they say it is guaranteed or other bs like that.
But if they are very clear about how it works I don't see why it is worse than any other gambling.
I do not recommend anyone to use ponzi sites, because they are bad and people will lose money so please don't neg trust me.
Disclaimer: I do not recommend investing in ponzi site! You will lose your money if you do so!