In medicine, people like to talk about quality-of-life-adjusted years. Why? Because there's no point in making somebody live more years that are subjectively bad (e.g due to treatment side-effects), rather than less years that are subjectively good. When it comes to policy-making that affects us all, it's time to extend that to the collective level.
We need to ask ourselves, how much suffering can younger generations be expected to endure to make the older generations live statistically a bit longer? Remember, the average COVID death is in their eighties, which is already beyond life expectancy.