So that the leader can use them to the situation's advantage.
Explanation:
If you have a project to create an advertisement for a band on a poster with 3 people with different talents and abilities you can assign who does what or mediate what gets done by who as the leader.
So say Sarah is good with color coordination and designing typographies or letters, so she can collaborate with Z who is amazing at drawing or photoshopping the actual pictures to get a coordinated color that is pleasing. Then Z is not only great at drawing but can take photos, so now Sarah can help Z get an idea about what colors to use in the band's photoshoot or with lighting. Then you have Rodney who may not be as creative as Sarah and Z, but Rodney knows a ton about what type of paper to use and how to print out colors to get the best effect. And maybe he's good at getting deals on ink and paper too, so now they don't have to worry about the logistics side for their project because Rodney has it under control.
But say you as a leader assigned that and didn't know these things and maybe your group is finding trouble assigning roles and so now the poster looks terrible.
But if you did, and you did find those things out, you could find a way to mediate the poster to look its best.
if thats confusing - you could compare it to baking a cake and having X Y Z where X is good at flavor mixing, Y is good at baking the actual cake, Z is good at decorating. As a leader you would want X Y Z to do the thing that they're best at, but if you don't know what they're good at you can't use it as an advantage to create the best outcome.
