Oftentimes the content isn’t the problem, it’s the format instead. No matter how good the speaker was, 90% of people were going to be disengaged. So the question isn’t “how do we find a better speaker?”
The question is “how do we change the format so that 100% of people are engaged?” If you start from that question, you likely won’t choose a sit and lecture format.
Maybe it’s a series of short activities. Or an interactive challenge in small teams. Either way, it’s always helpful to think of format first, and the “speaker” second.