The agency model does not solve any of this.
People are still selling books through the old model.
... and the market is speaking clearly:
Agency model books are more expensive than non-agency books
Agency model books sell fewer copies than non-agency books
Agency model ebooks are often priced higher than the paper book equivalent.
Consumers want to pay less for books. People are making money from selling cheap books - the rest of the market needs to adapt or die. Companies shouldn't rely on illegal business practices to ensure their antiquated business model survives.
Of course consumers want to pay the lowest price they can find of a particular product. Hence why piracy is so rampant. That doesn't create a healthy market though.