A full laundry basket can be perfectly reasonable on a flat floor. Put the same basket at the top of a staircase and its shape becomes the problem. It sits in front of the body, takes both hands, and can make the steps directly below harder to see.
Carrying less laundry helps, but now one trip becomes two. Better handles do not change much either. The basket still has to travel in front of you, with at least one hand holding it.
A laundry backpack with padded shoulder straps and a chest strap moves the clothes behind you instead. Both hands are free, so there is no need to choose between holding the laundry and reaching for the railing.
A full bag will not stay perfectly still behind you. Clothes settle as you walk, especially with heavier pieces mixed in. That gives the chest strap a real job. It holds the padded shoulder straps together at the front instead of leaving the loaded bag to move with each strap separately. On stairs, that is more useful than a few extra gallons of capacity.
The bag also stands upright, which matters more than it first appears. A backpack used only for carrying laundry still leaves you emptying the bedroom hamper into it before every trip. This one can be the hamper. When it is time to do laundry, the clothes are already in the container that goes downstairs.
There is no need to give every extra in the box equal attention. The included folding board may be useful for folding shirts, but it does nothing to improve the trip between floors.
Buyer feedback on the construction is mostly positive, although there are a few reports of weak stitching. That makes a manageable load more sensible than packing the bag simply because another sweatshirt will fit.
The useful change happens before the first step downstairs. The laundry is behind you rather than filling the space in front, and your hands are free for the stairs.
