serious question: why is qiyana allowed to buy boots if she faster without boots than i am with?

currently playing aram, im trundle i got the enemy qiyana has duskblade. and she is faster than me. she chased our adc and i chased her. and she outran me.

so why does this champ have the ability to buy boots? its clearly a waste of itemslot. she should be like cass, allowed to not buy boots rather get a "6th item slot for items" if she is faster anyways.

and our ashe has zeal so +5% movementspeed and fully upgraded boots... AND SHE IS EVEN SLOWER THAN I AM!

like wtf?

once qiyana has ghostblade ashe can just go afk its better for her team so qiyana doesnt get fed