I'm from post-earthquake Christchurch, currently the kiwi capital of earth-shaking emotions.
Some audiences so worked up, so worried, frustrated and angry, that many cannot hear what is being said to them - even things said two or three times.
PowerPoint is a brilliant visual aid, but only when it is used correctly.
Traditional use of PowerPoint stifles discussion and critical thinking, and dulls focus. It's boring. Slide after slide switches audiences off, steadily reducing their ability to take in information. You are wasting your time - and theirs.