Like the previous poster said tiling the saddle down can help relieve pressure points BUT the main reason it should be used to allow a cyclist to stay in a UCI legal position. The science is briefly touched on here: https://www.theguardian.com/sport/blog/2016/aug/15/team-gb-cycling-saddle-sore-medals
I have yet to come across a saddle that was designed to be ridden at an angle so having a significant tilt the saddle is often a sign of either: A) Having a poor fit on the bike B) the saddle is a poor fit for your backside. UCI rules limit the relative shape and placement of a saddle so riders can be forced into a situation where tilting the saddle is the only way to get some comfort.