The solution never tried: share the spoils of efficiency with your teams. Give them a percentage or even a few basis points of what they save back as charitable contributions to an organization of their choice. Watch how fast the bill will go down
Funny enough, for all the problems with studying business administration, they do teach this as part of the principal-agent problem. If the principal wants something done, and the agent has no incentive to do it, you need to give the agent some of the incentive so their interests are aligned with yours.
At the same time it's something you rarely see implemented by BA types, because they don't like to share.