I don't understand why you would be confused about this. just think like this:
If a person can double their money in 24 hours then that person would be the richest person in the world. And why the hell would someone who supposedly can double their money in 24 hours waste time creating a Bitcoin Doubler site?
Note that even if this person had $10 he could be very rich in a few months. one day she would have $20, another day would have $40, another day would have $ 80, another day would have $160, another day would have $ 320. imagine in a year how much money this person who supposedly can double money would have?
That's why it makes no sense for someone who is supposed to be able to double money in 24 hours create Bitcoin Doubler site
what these scammers do is run a ponzi scheme, and they already know that at most this ponzi scheme will survive for 3 cycles.
so if you are not someone from their group, someone who knows how the scammer operates, then you will lose money because you will never know the time to enter and the right time to leave.