Well, that's a good point. Many companies mock the popular MLM/Direct selling companies and recruit people promising huge returns. FTC says that a 'pyramid scheme' is one with an unlawful compensation structure - https://www.ftc.gov/tips-advice/business-center/guidance/business-guidance-concerning-multi-level-marketing
There are potential differences between MLM and pyramid scheme - https://www.epixelmlmsoftware.com/blogs/mlm-vs-pyramid-scheme