why randuins on lee sin?

is it to help you deal with being kited? because i keep hearing the randuins is a trap item and that deadmans is the new go to item, seems pretty useful on lee sin with the passive speed and the momentum hit slowing someone by 75% on hit for 1 second, i know randuins slow is much stronger but does that justify the weaker stats? i just thought it was strange cause most lee sin guides, even to date use randuin as well as what people are showned to build on probuilds.