The goal isn't to make it impossible to do insider trading, it's to set some controls and have consequences when they aren't followed. The middle man scheme yo

The goal isn't to make it impossible to do insider trading, it's to set some controls and have consequences when they aren't followed. The middle man scheme you mention would be illegal under OP's idea. So prosecute everyone involved. The more people involved, the harder to hide it. Your argument is basically "it doesn't make sense to have murder be illegal because the law won't prevent the bullet from flying."