A long lunch is not an indulgence. It is an instrument. It is how, in many organisations I have worked with, the real work of trust gets done.
An hour at a table, without slides and without a clock visible on a screen, is one of the few formats left that allows two people to disagree without it becoming an incident. The food slows the pace. The shared table flattens the hierarchy. The absence of an agenda permits the actual subject to surface.
Calendars now treat lunch as a thirty minute gap to be filled. The cost of that compression is rarely on the calendar.