In general, since the first televised “debate” (they aren’t), the quality of candidates and Presidents has declined fairly steadily.
It’s all about getting the “sound bite”.
1960 Presidential Debate #1 - John F. Kennedy vs. Richard Nixon 9/26/1960
Sixty years ago, a world of difference...yet Kennedy, having the opening statement immediately oversteps the debate rules introducing foreign policy statements in what was supposed to be clarification of his domestic policy only, very smooth and slick.
Nixon was also very smooth, adding responses to JFK in his opening statement.
Very instructive to for those whose grand dads watched this in real time. Oh, and no teleprompters.