We spend an awful lot more, in terms of resources, money, time and effort, on trying to shorten lifespans than we do prolonging them. The immorality isn’t the expenditure on life extension technology against basic medical care, it’s military expenditure against basic medical care. We find it a lot easier to spend money to kill than we do to heal.
Leaving that aside, it’s absolute madness to suggest that we should reduce research on the leading edge of medical science on the basis that only the rich can afford access to it initially. The real cost of technology comes down quickly over time, whether it be genetic sequencing, heart valves or phones. When penicillin was first developed and used it was expensive and difficult to produce, it was almost two decades before industrial R&D came up with a cheap and effective way to mass produce it (as usual, the investment wasn’t made until it was militarily desirable).
The cost of new technological developments is tied into the difficulty producing them but as the industrial apparatus and infrastructure needed for mass production of any item is built and perfected, the cost reduces. This is why the life span in the poorest country on earth, according to the article, is a little less than 50% above what it was throughout human history.