... But then you would have to count the bias against single founders and all the investments they didn't get thanks to that bias. And also count all the accelerators than discarded them for this issue.

Plus, there is also the "fake co-founder" tactic some people use in order to avoid this bias from others; so you would have to count those as well, but that data is not public. So yeah, I think you are trying to count the uncountable.