Having to compete for each task order is thought to reduce costs to the government. Of course having to compete each task brings its own additional costs which don't necessarily make the cost saving proposition true. The big benefit I see to this contract is that it helps prevent vendor lock-in. I don't worry about the next 10 years and $10B, but what happens after 10 years when the DoD is now locked in to proprietary AWS cloud features which make migrating to a different vendor technically and fiscally near impossible.