A numerical ranking can obscure questions about distribution, suffering, and the distinction between existence and nonexistence. Attempts to avoid the Repugnant Conclusion face additional puzzles about consistency and adding lives. These are theoretical comparisons, not demographic forecasts or instructions for judging the worth of actual people.
Sketch a population in which everyone is doing well, then add one person whose life is less good but still worthwhile. Ask whether the addition improves the world, whether it harms anyone, and whether those are the same question. Next add severe suffering elsewhere without changing the total. The exercise helps separate aggregation, distribution, and person-affecting reasons. A population theory must handle these comparisons consistently rather than selecting a different measure whenever the result feels uncomfortable.