Indeed. The comment about "on this level" shows a misunderstanding about high level play. It's at low level play where it makes sense to play it out because a l

Indeed. The comment about "on this level" shows a misunderstanding about high level play. It's at low level play where it makes sense to play it out because a low level player is less likely to realize they are in a losing position, and a low level opponent is actually fairly likely to make a mistake that could turn the tide. At high levels of play, continuing to play implies that you think you have some chance of winning and that it is therefore worth both players' time to continue the game. If you know you shouldn't win, you are either implying that your opponent may make a stupid mistake that would let you win (an insult to their ability) or you are assuming a right to their time for the mere formality of finishing the game. At a low or mid level of play, it might even make sense to say that you know you should resign, but you'd like to play it out to see just how the checkmate happens and thus learn more about the game (and giving your opponent that chance to take the resignation rather than assuming you may have their time), but no one is going to learn anything from playing out a losing position at this level of play.