Do you think people who beat, rape, shout at, con, and otherwise abuse others are happy people? Do you think you can abuse a child and still be a genuinely happy person? Do you think you can sexually and physically abuse someone and feel authentic happiness?
Do you think it really matters that some of them have money or a respectable job? Sure, money can provide a sense of safety, and having social power can indeed be useful. But ultimately, the price that they pay for it is an even bigger loss of self. This makes their feelings of misery and self-loathing even stronger. And its not like they wake up one day and change their mind and behavior. All the lies, deception, hiding, being abusive, creating stories and justifications, fighting with people all of it continues to spread and pile up.
Eventually decent people dont want to associate with them, but they are older and more miserable, so they start feeling more and more desperation. Some of them try to change their behavior out of fear of mortality or loneliness or need for narcissistic supply. Some try to guilt-trip or shame or bully others into giving them resources, but it becomes harder and harder.