Staking yield is the amount you stake times the annual rate you enter, for the period on the form. A price change you enter is applied as a separate impermanent-loss or value-change case so the token count and the dollar value are not treated as the same thing.
Staking $10,000 at 5% for a year adds $500 if the token price does not change. If the price falls by half, the dollar value of the stake and the reward falls with it. The page shows the rate you typed, not a protocol’s current reward.
Lockups, slashing, validator fees, and taxes are not deducted unless a field asks for a fee. The rate is not a live on-chain quote.