Lives make waiting part of the game. When lives run low, the game creates a natural reason to return later. You are not just bored; you are checking whether the next attempt is available.
Episode Race rewards speed. King's Help Center describes Episode Race as a competition where you race through levels against other players, with faster progress improving your chance of winning boosters and gold bars. That turns "one level" into "keep going while I am ahead."
Boosters make sunk cost feel real. When you use a booster, extra moves, gold bars, or a timed bonus, stopping can feel wasteful even if you already played longer than planned.
Events keep the map alive. Candy Crush has events, side quests, races, rewards, and seasonal hooks layered on top of the normal level path. There is almost always another small thing to claim or finish.