That conversation has been going on since long before COVID-19. For example age is one factor in allocating scarce transplant organs. Other countries with socialized healthcare systems sometimes explicitly use Quality Adjusted Life Years (QALY) in deciding whether to pay for expensive treatments for elderly patients.
So is he. QALY analysis is used to allocate all treatment in places like the UK, realistically in other places too. Basically a very expensive treatment that is only expected to increase your lifespan by a few months if you're already very elderly may not get funded if there are other interventions with better cost/benefit ratios available in the queue. This obviously affects nearly 100% of the population in the sense that most people will make it to old age, and even the non-elderly are affected by getting treatment they otherwise might not have done.
Not saying that those 400K doesn't deserve to be saved, they are absolutely deserve the care but if you are doing it at the huge expense for other people then conversation is unavoidable.
You build in the assumption that policy responses to a pandemic will harm the economy, and then don't do any work to establish that policy responses in this pandemic have prioritized lives over the economy, or to demonstrate that policy responses that weren't used would have been similar, etc.
I think, clearly, that there is a debate to be had about the value of lives that are nearly at an end no matter what, and lives that are just hitting their prime.
