People wander off the topic. Participants spend more time digressing than discussing. Nothing happens once the meeting ends. People don't convert decisions into action. There's plenty of conversation, but not much candor.
People make the same mistakes.
Practice makes perfect. Monitor what works and what doesn't and hold people accountable. These things make a huge difference. Fast Company says the capacity for misunderstanding is unlimited. The problem isn't that people are lazy or irresponsible.