I don't see any clear advantage for people to live much longer than they already do, on average, in developed countries. One could argue that people being healthy for a longer time could allow them to be active and be less of a burden to society. But they would still eventually become old, so the problem would remain. Except if we found a way for people to only die of sudden causes, while they are still in their prime, which wouldn't be such a good idea either. Therefore I wonder if trying to find a cure for aging itself (rather than to a particular disease, including progeric diseases) will really be that useful, apart from the intellectual satisfaction that working in such an interesting field can bring.