Drug Cartel heads pull in lotsa money by providing to drug addicts what they want
Robber Barons got very wealthy (JP Morgan, Andrew Carnegie, Andrew Mellon, John D. Rockefeller) by unscrupulous means
Heads of state who steal money from the people and get obscenely wealthy while the people suffer
Disreputable businessmen who are always getting sued for fraud or suing someone or stiffing someone
Or the old-fashioned way. Creating something millions/billions of people need, can use, can afford
