While this is logical, the more diseases of old age we cure the longer and better the quality of life the elderly get, and treating amyloidosis is one small step towards that.

It depends; for instance there are a lot of cancer treatments that effectively replace a quicker and potentially comfortable death with a prolonged period of suffering. And my argument isn’t that these treatments are universally worthless, but that it’s perfectly fair to observe that their benefits are marginal at best.