Best before and sell by is a guarantee. Its the company saying this product will last until X date. Just like your car doesn't become unusable when the warranty runs out, neither does bread, especially when you make some attempt to store it properly, because best before dates are based on the opposite.

As I mention elsewhere in the thread, these dates do not have any legal meaning at all for the manufacturer. They do have meaning for the vendor (the grocery store), but that's not what people generally imagine is going on.

Even the phrasing "best before" explicitly doesn't guarantee anything; a manufacturer would be crazy to make such a guarantee.

I would expect bread consumed before the best before date not to be stale, if it was I would expect to be able to get my money back, I wouldn't expect the same after the best before.

One problem with food is that there are too many variables about how it's stored after it leaves the store. For example, bread can go stale if it's not stored in an airtight container.

The best before probably takes into account the worst case and is set low accordingly. I go to the effort to store bread appropriately so that lower bound is no longer particularly relevant to me.

Absolutely not, if you think bread going stale is relevant to the expiration date. (Which it isn't.)

If you leave bread exposed to the air, it will go stale almost immediately, long before a one-week expiration period has elapsed. The expiration date is obsolete as soon as you open the product.