Over selling being necessary is a drag, & it exists in internal politics too. It's priced in, so giving someone a realistic schedule/budget causes two problems:

Over selling being necessary is a drag, & it exists in internal politics too. It's priced in, so giving someone a realistic schedule/budget causes two problems: they lower your expected range by thinking your realistic numbers are optimistic, & it breaks the lull that some project is going to save having to put in hard work still