Pareto's law states that 80% of the results come from 20% of features (effort) of your application. Bear this in mind when planning the next scrum/delivery.

The best engineers are those who can estimate the effort of new requirements and they are the only with enough information to refuse the 80% that is not in the optimal next scope.

Own it! This is not the army, they pay you to think and take decisions and responsibility so speak up if you consider the requirements proposed are superfluous.

The worst code you've ever written is the code that is no longer used. Is called YAGNI (You Are Not Gonna Need It).

The best code you've ever written is the code you didn't write, simply because it's the only that never fails.