They're not paying you $1000 for a wordpress site, and they're never paying $1000 on retainer. The rest is also a total fantasy.
This is a misleading example because restaurants and food already operate on razor-thin margins; restaurant software is legendarily hard to break into and make money in.
Source: tried to start a "make websites for food trucks" business years and years ago, talked to hundreds of food truck owners, and learned that they're largely running food trucks because they like the hours, the freedom, the scale of the business. They can make decent cash without maintaining a space or even necessarily operating outside lunchtime. They don't really need to drive more business, and won't really anyway--their fortunes are tied to geography and the economy overall.
If you have an example from your own life, please use that instead of a fictitious one that is misleading and kinda wrong.