It has nothing to do with bitcoin, that's the first thing that you need to understand. That's why the are called scammers because they take advantage of anyone in crpytosphere. You just have to think logically, no one can passively earn that amount of money just by watching ads. If you really wanted to earn here, you need to work your ass off, just like regular jobs in the offline word. I do hope that this is a big lessons for you and your friend, not to blindly trust anyone with your precious crypto.
sadly to say, these scammers just used the name of bitcoin to attract naive users. they are not in any way earning btc thru watching ads. they just look for certain activity that will give seemingly "valid" source of income. return of 4.6% daily from your investments seemed really a ponzi scheme to me. so they are just using the deposit of newcomers to pay the older users. not a new scheme but still people are jumping on this kind of too-good-to-be-true roi. and once they collected enough money for their pockets, they are gone. i dont know how many users will still fall on this very old tactic before they really need to learn their lessons in a hard way