Sometimes it's just the simplest way to accomplish something. It's just another tool for doing parkour through the state automata. Sometimes you know you want to do something that's a jump from a precise place at some point in the very near future so you go there and shield drop and now you can eg sh bair. Or you could be fox on a spacie at upthrow usmash kill % and they do no DI so you need to move sideways a little before waiting for them to get there, so you dash dance, shield at the right spot, and upsmash when they get there.