Are there disadvantages to storing bread in a vacuum box? I love fresh bread, and when I buy it I store it at home in a plastic bag. After 2-3 days it has probably lost about 60% of its overall quality. I've been using some vacuum storage bags and found that the bread can be great up to a week later!

This made me think about how I'd love to have a box or chamber on the counter that I can just dump my bread in and vacuum most of the air out. It would be stationary and much more practical than bags, which require cutting and subsequent disposal.

What are some of the primary barriers to this being a practical tool? I'd imagine many households would want this!
Bread gets dried out and stale through retrogradation which requires moisture.  Your vacuum bags are not keeping the bread fresh because of the vacuum, they are keeping it fresh by providing a very tight seal that prevents the bread from absorbing moisture from the atmosphere.  A larger vacuum box would provide the same protection from moisture but it might dry the bread out since the moisture in the bread would easily evaporate at the lower pressure.  Also keep in mind that neither a vacuum bag nor a vacuum box will prevent mold from eventually growing on the bread.

The biggest competition to a vacuum bread box is the freezer that most people already have in their kitchen.  Frozen bread can go for many weeks or even months without going stale and without any mold growing on it.  The only real risk to the bread is freezer burn if it is not sealed tightly.  Use vacuum bags to seal your bread tight and it can last a very long time in your freezer.