Nothing is surefire, but I’ve seen the S&P 500 informally considered the baseline, especially when comparing actively managed funds. If you’re paying more and under performing the S&P 500, even if making a profit, you’re loosing out.

With regard to the point about everyone being millionaires, from a macro economic lens, all the dividends you receive from investing in the S&P 500 is because they’re charging more than enough for a product to cover operating costs, business expenses, etc and still have enough to pay out share holders. This means someone somewhere is loosing out, and that money is being transferred from them to you through the companies.