Of course psychopaths exists. Most people are not psychopaths, though. And especially the CEOs you mention may have problems to persist.
I still prefer those "CEO psychopaths" to people feeding on government money (people in useless jobs paid for with taxpayer money).
https://www.washingtonpost.com/news/on-small-business/wp/201...
I personally think that the "successful pyschopaths" meme is also way overblown, but I don't really know. I think being a psychopath is actually a deficiency, not a super power. Also in business I think people who help other people tend to be more successful overall than the stereotypical ruthlessly selfish people.
Edit: I think you added the link later on, that cites 21% of CEOs to be psychopaths? I would wait for replication on that one. It reminds me of another thing I read where reading about economics allegedly turned people into psychopaths (which is of course bullshit - just because you learned about rational decisions, as perhaps most CEOs do at some point, doesn't mean you are a psychopath). I suspect the questionnaire or the study they used to determine the "21%" number may in fact be motivated by politics.
Of course crooks exist. Most people are not crooks, though. And especially the professionals you mention may have problems to persist. Like the shoddy dentist will be busy with lawsuits presumably.
I still prefer those "private crooks" to people feeding on government money (not meaning people on social security, but people in useless jobs paid for with taxpayer money).