I often listen on radio or watch on television as very key, prominent, important people speak on and about their areas of expertise. So many, yes SO many of them are very poor presenters when it comes to their qualities of speech, diction and (on television) gesture.
The ‘matter’ factor of their offering is fine. They know their subjects. But it is their manner and method of delivery that let them down. Leaving lasting impressions of mediocre delivery I am sure, is not what the speakers want. But unfortunately that’s the way it often goes.
And all for the want of a little fixing!