***Ladder Drills and Quick Feet Drills Don't Make You Faster*** What they do do is get your nervous system to become capable of a faster rate of contracting the muscles, albeit without producing much force. However, by using these drills to "wake up" the CNS and develop that ability to contract and relax muscles quicker before you do your true sprint and change of direction work you make the "fast feet" drills improve your actual SAQ work. Don't get caught up by some of the flashy Instagram videos, use fast feet drills to potentiate/facilitate faster movement during your sprinting, that's how they'll help you get faster.
Ladder drills and fast feet drills won't make a better athlete by themselves!
Use them properly.