It's the only part of the game where "only move" positions are truly common and they are often quite counter-intuitive. Endgame is where you find out if you understand the game at the most central level. Comparatively, middle game and opening are areas where more general ideas drive the discussion to specific calculations.
What gets me excited about endgames is the unique nature of that part of the game. Finding out what a lone piece is really capable of doing. And then taking that information to my OTB games where it pays off very quickly.
I find opening study to fascinating and have a genuine love fo rthat phase and find middlegame study like tactics and technique to be entertaining but when it come to the endgame I bore my brains out. I just can't take studying that phase for like 10min without getting severely bored but I do know that just as much as I love opening study that there is someone who loves endgame study. So my question is what truely intrigues you about the endgame or gets you exciteed aabout it so that I can find the same joy perhaps ?