@jeff_bloomer & @Jennifer_Dungan have both provided some great examples,
I'll throw in another one as well: Situations where you can have
multiple settings applied at once, and you want to see which single
setting is the most applied. Let's say you have a product list page, and
you have the option to apply multiple filters, and have an event fire
"apply-filter" after selecting multiple options. Instead of having
"new_home_blue" being set as the value, you will get the values of
"new", "home", & ...