Most players resign when they know the position is lost. Sometimes they are wrong. That is, in a game I played yesterday, my opponent resigned after my blunder made the position even. He may have thought that I was winning material due to a back rank checkmate threat. If so, he overlooked that the checkmate threat only wins back the sacrific d material.
I will play out a lost position if there is any reason to believe that my opponent cannot complete the task in the time remaining. I will underpromote pawns if my opponent does not resign.
Abandonment is poor manners akin to starting threads about rematches. Maybe worse.
What do you people think about blitz games, in case you are in a lost position? Keep playing and try to win by time? Or abandon? I just want to check what is more fair with ethics.