On the bike, sternum strap is crucial. Waist straps typically don't work for me because my torso is super short (5'6" with 32.5" cycling inseam).

I usually end up with packs with waist straps. My current Marmot Zephyr has two padded bits extending from the body of the bag where the straps are attached. They have pockets in which to stow the straps and zippered mesh pockets on the front of them in which I typically store my phone (right) and keys (left).

If I had a taller torso or found a pack with a higher waist strap I'd probably use it on bike a lot.