Your view is very considerable, I was also had the same thought a few days ago when I watched a lecture on Shopify where peoplele sell there own products and even do dropshipping. I came to realize that, even if a person who have not money (depends on parent's money) or have no source of income (student), still saving funds to buy new t-shirts, new watches, shoes, spending money on lifestyle, instead of spending the money on themselves as in terms of skills.

Then I thought of the cause, and came up with the advertisement companies, for example a friend "X" is doing some shopping, how these brands use data to manipulate the mind of X so that he do more shopping, they show him cool ads, relevant to his likeness, and onces he saw too many he made up his mind to buy. So in this era, no only rich people are buying luxury brands,  poor or mediocre are also buying products (unnecessary).

So overall, money is flowing from top to bottom, but you are right we can also make money by buying the stocked of those products which are being bought by these rich people.