The purpose of a speech is usually to convince an audience of your point of view.
It should be short, concise and moving, but the State of the Union address has become a laundry list without much of a cohesive tone.
Then the press office releases it beforehand, and talking heads relate their views before the oration is given.
If Lincoln had done that at Gettysburg, we will never have read his poetic words we all love. A good State of the Union address was John Kennedy’s second summary that concluded that all was well “on the Good Ship Union.”