It isn't just half an hour. It's half an hour of being almost forcefully yanked out of the zone, which may lead to hours of lost efficiency. The idea that we just measure by the time it takes to talk to people plus a minor overhead, is part of why this is being normalized so often. Yet that idea has never been proven, and there is more suggestive evidence of the opposite. Nor has the value of such a "more accurate" estimate ever been shown, beyond a few actually critical deadlines (extremely rare in the field of software dev). Especially considering so many projects even under harsh estimation rules go overbudget and overtime anyway.

That's before going into the long-lasting effects of such a dynamic, and potential escalations. The most obvious one: dragging in part of, if not the entire team, for every little thing.