The guy in that article says in his best year he made $135,000. Paddock supposedly reported a $5 million profit for 2015.
That interview was in the 1990s. Everything has gone up since then. I also imagine some that do this for a living are better than others.
He was also playing quarters. Paddock was playing big money. The guy in the article balked at $1 games because you need a big bankroll. Paddock apparently had a big bankroll. Also, the guy in the article avoided the $1 games because of taxes. Paddock needed the taxes to clean the money. (??)
The article also said that the particular machines he played payed out over 100%. IF that was once true its not now. They are set to something like 97.5% pay out. The longer you play the more you succumb to the law of averages.