I know a lot of zombie startups that make little to no money, yet they raised seed rounds that will last them 2 years.
I know a handful of other startups that were "acqui-hired" but the founders did not see any returns (and the VCs didn't even get their initial investment back). Even in the case that the returns were 1.2x the initial investment, these are not the winners that investors are looking for.
I would love to see a more in-depth analysis of these situations, but unfortunately, many of them are not publicized.