Once you own $WANNA (from Exchange or Farming), you can sell it for a profit. But Staking offers users another way to maximize profits.
When you deposit and stake your WANNA, you will receive WANNAx back. And 0.03% Fee from Swap will be used to buy back WANNA and deposit into staking pool. This makes the price of WANNAx go up. In other words, stake WANNA to earn more WANNA.
Thus, participating in Stake to earn more WANNA for users. Especially if the price of WANNA in the market increases, the profit will be maximized.