I am not currently affiliated with any MLM or DS companies, though I have been in the past. One company I worked for ended up going under and sticking consultants with thousands of dollars owed to customers who never got their items. It is also very time consuming since so much is dependant on social media for sales these days. Much more than a 9-5 (regular job) if you actually want to come out head in the long run. I did very well with a DS cosmetics company a decade ago, though the game is totally different these days. Back then it was face to face interaction and I excelled at it, now it is building a social media following (something I do not have the hours to devote to.
The biggest mistake most people make is they forget the 'You have to spend money to make money' adage when pursuing DS or MLM jobs. People want a demonstration and in order to provide testimonials, and demo's you have to buy the product yourself.
I do think the companies make much more profit off of their reps than the reps will ever make off of selling their products.