1440p/60Hz for:
Graphic design, photoshop, 3D, video/music editing, encoding (due to larger screen real estate = more working area)
Slow-paced games such as strategy, puzzle, turn-basis games (due to lower fps/refresh rate but larger screen real estate)
1080p/144Hz for:
Fast-paced games such as FPS, racing, competitive gaming, some RPG (due to higher refresh rate = smoother gameplay)