I agree that Nunn's endgame book wouldn't be the first thing to study as a beginner because you likely will lose (whether you are checkmated or not) before you even get to the endgame if you haven't studied tactics.
I disagree with these. Many games of a novice vs novice reach endgames. Knowlegde of endgame will help novice beat fellow novice. We must remember many novice likes to trade, many novice are afraid of queens and likes to trade it. Nunn's book is excellent. But I suggest Winning Chess Endgame by Seirawan or Pandolfinni's Endgame course as first endgame book for beginners. Nunn's book might be too daunting for them.
I agree that Nunn's endgame book wouldn't be the first thing to study as a beginner because you likely will lose (whether you are checkmated or not) before you even get to the endgame if you haven't studied tactics.