Basically, people do what the law enforcement - like police and judges - say because they go to jail for a long time if they don’t. There are plenty of other punishments that aren’t jail, but those are really only enforced with the threat of jail time if you don’t comply, so it all comes back to jail in the end. Nobody’s going to come after Trump to put him in jail because he’s the president, and even before then, he had enough money to make sure nobody came after him anyway.

Nobody but the wealthy know exactly how they get away with their crimes, but I’d imagine some high-ranking members of the police force and probably several other people from other government agencies are willing to look the other way for a bit of cash, which allows the people who have that cash to essentially treat every crime like nothing more than a fine.