With Uniswap, liquidity providers only earn the pool’s trading fees when they are actively providing said liquidity. Once they have withdrawn their portion of the pool, they no longer receive that passive income. In addition, even if they were early liquidity providers when the protocol acquires traction, (larger and wealthier) stakeholders like venture funds, exchanges, and mining pools that will contribute a significant amount of capital to the protocol may dilute their return.
With PoWSwap, one can also provide some liquidity into a pool and earn rewards in the form of POW tokens. Even if you decide to stop taking part in the liquidity provision, those $POW tokens will still allow you to continue earning a percentage of the protocol's fee, which has been accumulated in $POW, unlike Uniswap. As an early adopter to help provider liquidity, you become a significant stakeholder of the protocol.
The amount of LP tokens you stake relative to the total amount staked will determine how much money you will make through staking. Your assets and accompanying reward profits will progressively diminish if you stop providing liquidity.