It makes no difference, because one must also account for every other failed startup the founders had or will participate in, along with other opportunity cost. In fact, the final ROI of VCs should be higher than the founders' because they get the bulk of the equity in exchange for their investment.
Yes, just invest in a mutual fund. Overall VC returns are in line with the broader market at best, and are often worse. (Source: http://www.avc.com/a_vc/2013/02/venture-capital-returns.html)