As a general rule, modern-day capitalism produces products based on whether you can market it to somebody with money, not on actual results. For a lot of markets, the revenue is nearly as good and it's much cheaper to make something that doesn't work well, or doesn't work at all.

The most obvious example here is make-money-fast schemes. Those things never work; if they did, they wouldn't be offered for sale to randos. But there are a ton of others.