my question to you is: have you ever tried any of these strategies before? were you successful?
No, they are simply variants of the martingale, which is a strategy that has long been known not to work but that people insist on continuing to try, in some of its variants, and others continue to promote. You can be successful, but just as you can be “successful” in a casino session by being lucky or having a favorable short-term variance. As you increase your sample size, the probability of losing keeps increasing.
Yes, that is basically the whole thing.
The more a gambler continues betting, the closer it gets to the expected return, which is basically negative for the gambler.
That is, a gambler in the long term will lose money. They can get lucky in the beginning, but if they continue gambling it is almost guaranteed that they will lose.