They can do it with a real business briefly. The thing is, you open a business to make money, and in order to make money people need to pay you, not the other way 'round. Fake reviews become real reviews very quickly if you actually exist.
THAT SAID
Neil Patel set out in May to have a $100k/mo online business within a year just as an exercise. It's been alternately fascinating and horrifying to watch. On the plus side, Google clobbered him once and he ran into some of the fundamental issues of fiverr. On the minus side, the shithead has a thriving health blog without knowing the first fucking thing about health.
There's this whole bizarre phantom economy in SEO - fake likes, fake reviews, fake tweets, fake businesses... I think one reason it persists and one reason nobody really shits on it is that it doesn't generate real revenue. Yelp exists for the benefit of brick'n'mortar establishments and if you suck, you'll get sucky reviews (people are something like 5x as motivated to write a negative review as they are a positive one). If you have seventy glowing posts on Facebook followed by five heinous ones, everyone will discount the seventy glowing posts. Reputation management is a lot more than buying a bunch of likes and retweets, and that's why these articles about how easy it is to get likes and retweets never really change anything. In the end it matters, but not nearly as much as they'd have you believe.