Ljótipollur is strongest as a supporting stop, not a lone objective. Pair it with places that already justify the Highlands access decision.
The obvious pairing is Landmannalaugar, where the main decision is hiking, hut-area context, and colored rhyolite mountains. If you are comparing crater-lake pauses, Bláhylur / Hnausapollur gives the nearby blue crater-lake option. If you want the broader landscape story, Fjallabak gives the reserve-level frame that explains why crater lakes, lava, and rough roads sit so close together.
For a longer interior day, compare the crater with Eldgjá or Sigöldugljúfur only if the roads, daylight, and group energy support the extra movement. Those stops can make the day richer, but they can also turn a clear Highlands plan into too many separate objectives.
If the Highlands plan weakens, use South Iceland as the practical fallback geography. The lowland route may be less unusual than Ljótipollur, but it is often the stronger choice for first trips, winter-sensitive plans, or travelers who need simpler driving.