I don't get this: "But remember: if you limit yourself to detecting uplifts of over 10% you will miss also miss negative effects of less than 10%. Can you affor

I don't get this: "But remember: if you limit yourself to detecting uplifts of over 10% you will miss also miss negative effects of less than 10%. Can you afford to reduce your conversion rate by 5% without realizing it?" You'd potentially lose 5% CR if you ship the variant even when it doesn't show a detectable uplift. Why would you do that?