The phrase "to grow the pie" means increasing the total amount or value of something. It refers to expanding and making a resource or opportunity bigger so that everyone involved can benefit more. Full definition
It's called growing the pie, creating more decent jobs that pay more. (entrepreneur.com)
A person who favors equality is willing to accept lower efficiency, while those who favor efficiency focus on growing the pie rather than cutting it evenly. (firstthings.com)
We can become so preoccupied with competing for the limited amount of pie that we stop thinking of innovative ways of growing the pie. (slaw.ca)