Saying the user haven’t got to be responsible for his brothers action is an ignorance to the duty you owe a sibling. I don’t know but somewhere within our DNA or subconscious, we do hope our family members, relatives or friends that we do do care about don’t walk down the same road we did once or are way too familiar with to lead just no where.
yes, I understand that. however, because are still relatives sometimes we have the feeling not to let relatives get into trouble. but sometimes there is enough resistance that occurs when a brother has seen his partner make a successful withdrawal. and that means that anything we say or warn about will not be taken into account.
his job of giving advice has been done and if his brother doesn't accept it, then forget it. We don't know the end, but we know it's risky for anyone. and those experienced in this matter would of course avoid it.
Most of the time, people make mistakes first before realizing that they are wrong. Very often to happen that some people have fallen into investment scams because they never listen to other's advice. Very unfortunate, but never let it happen to your siblings since you already have an idea about the Ponzi scam scheme which is likely they are into now. They might argue with you OP but must have to be firm in your position and convince them that they are wrong and help them understand how real crypto investment works.
it is possible that when his brother realizes that his investment will fail and cannot make withdrawals, his brother will seek Op to provide a more in-depth explanation. and that is what will make his brother aware of the risks he faces.