I worked in a simple pizza parlor like that when I was in high school. Same deal. No credit cards. Only credit cards didn't exist 55 years ago.
He's doing his thing and has a limited ceiling of 40 pizzas and a long line to eat them every day. Obviously he has a limited income you could probably figure out if you took the time. Success is what you define and make it.
As for the article, it is one man's opinion it is the best pizza in America. The opinion could be legit if it hit his taste buds just right. The aura surrounding a pizza is just as legit in making it the best to someone's senses.
Technically there is no best pizza in America. 330 million people could not possibly taste them all or let alone agree. Heck, you could take the acknowledged top 10 food critics in America or the 10 most knowledgable people on this board and probably not reach a consensus if they had to choose, make a blind taste and make a blind submittal without the influence of others. Like in all ratings though there is always the influence following effect. That's how some pizza parlors stand out. Cable food features, magazine features, Internet rating articles, Google list placement, celebrity endorsements, etc. They all feed on each other and grow because everyone putting together such information has to initially research.
All such reviews are worthwhile. Most have to be legitimately good to get noticed and mentioned. With so many pizzas and so few opportunities they serve a purpose to winnow down choices to better odds.