The point that it’s better to save people with better lives than people with worse lives, all else equal, does make sense (at least from a utilitarian perspective). So you’re right that [$ / lives saved] is not a perfect approach. I do think it’s worth acknowledging this...!
But the right correction isn’t to use VSLs. The way I’d put it is: a person’s VSL—assuming it’s been ideally calculated for each individual, putting aside issues about how governments estimate it in practice—is how many dollars they value as much as slightly lowering their chance of death. So the fact that VSLs differ across people mixes together two things: a rich person might have a higher VSL than a poor person (1) because the rich person values their life more, or (2) because the rich person values a dollar less. The first thing is right to correct for (from a utilitarian perspective), but as other commenters have noted, the second isn’t.
My guess is that the second factor baked into the VSL is bigger in most real-world comparisons we might want to make, so that it’s less of a mistake to just try to maximize [$ / lives saved] than to try to maximize [$ / (lives saved * VSL)].
The point that it’s better to save people with better lives than people with worse lives, all else equal, does make sense (at least from a utilitarian perspective). So you’re right that [$ / lives saved] is not a perfect approach. I do think it’s worth acknowledging this...!
But the right correction isn’t to use VSLs. The way I’d put it is: a person’s VSL—assuming it’s been ideally calculated for each individual, putting aside issues about how governments estimate it in practice—is how many dollars they value as much as slightly lowering their chance of death. So the fact that VSLs differ across people mixes together two things: a rich person might have a higher VSL than a poor person (1) because the rich person values their life more, or (2) because the rich person values a dollar less. The first thing is right to correct for (from a utilitarian perspective), but as other commenters have noted, the second isn’t.
My guess is that the second factor baked into the VSL is bigger in most real-world comparisons we might want to make, so that it’s less of a mistake to just try to maximize [$ / lives saved] than to try to maximize [$ / (lives saved * VSL)].