Also called wishful thinking... Often such measures do definitely not work. There is even an internet law named for this: "When a measure becomes a target, it ceases to be a good measure".
Said another way, I don't say no a lot, I put prioritization up front and tell them that we are sacrificing other deliver items.
That is a decision that an exec can work with, mediate between teams, and builds mutual respect for senior leadership as you don't break promises you've already made, unless there is mutual agreement from the business.