Why can't someone just start a "scheme" more legit like have a max limit of "0.01" bitcoin that can be doubled, so no minimum, no maximum, just 0.01, doubled on the back of everyone else, take your cut and everyone wins because 0.01 is easy to fulfill where 1 BTC is a lot harder.
These schemes don't work.
To double the first person's deposit, you need a 2nd person to join.
The double the 2nd person's deposit, you need a 3rd and 4th person to join.
To double those 2 deposits, you need 4 more people to join, making a total of 8.
To double those 4 new deposits, you need 8 more people to join, making a total of 16.
and so on.
Each each step you need twice as many places as in the previous step.
After 10 steps you need over 1000 players.
After 20 steps you need over a million players.
After 33 steps you need everyone in the world to be playing.
Do you see now why these schemes always fail, and why you shouldn't get involved?