A full time VC might see 2000 pitch decks per year, meet with a few hundred of those companies, and end up investing in 5. So they are picking what they perceive to be the top .25% of all pitches they see. If they invested in 20 companies, it would be the top 1%. If they invested in 200 companies, it would be the top 10%. But because these companies are ranked, the expected outcome distribution of the VC's #1 company should be a little better than the #10 company, and a lot better than the #200 company. The further down the list you go, the worse the expected value -- even though some of the lower ranked companies may turn out to be amazing.
So you can't just 40x the number of investments you make and say "expected value is the same but variance is now much lower!!1!" because you would be lowering your bar a lot by expanding the # of investments. And your variance would go down considerably, but so would your expected value.