Think of it like a house, and the footwork is part of the foundation, you never hear anyone talking about the foundation unless of course it's bad, then the whole house is bad until that foundation is fixed.
Yep, we coach our kids to always play on the ball of their feet. We coach our QBs to always play almost on their tippy toes and to bounce a little bit. Keep your feet live so your body adjusts to whatever is going on more quickly.
Also, throwing from the ball of your feet allows you to pivot more and put more power behind your throws. We coach our kids to use their hips and feet to get more power on their throws rather than use their arm.
You can put all of the force in the world behind your throw with your arm, but chances are that throw will be more inaccurate than if you use your feet and hips to put the force behind the throw.
Arm strength is important for that velocity, but your feet and hips are important for that trajectory, distance and accuracy.