This is a (common) fallacy that could be applied to any funding or focus decision. It reduces to "Why focus on X when Y is more important?". You could use your same examples here as an argument for why not to support space exploration, or environmental conservation, for example.

Government budgets are finite: prioritization is not a fallacy but comes built-in, as anyone who has written a grant application knows.

We have a whole host of societal functions that are not geared to cope with longevity: including social security plus the associated tax-rates

I don't follow your social security point; could you please explain? Thank you.

Medical & aged care social security costs are tied to deaths of recipients: the bigger the delta between retirement and death,the greater the cost. If the average lifespan grows rapidly, current social security funding will become insolvent, requiring taxes to be raised and/or retirement age to bw raided to leep the current average delta: neither option will be popular with the electorate.

I think you misunderstand the intent behind longevity research and goals: It's to eliminate the senescence period, or to slow everything down if unable to achieve that.

You only need social security if you’re unable to work. If we increase healthspan to the point that you can maintain the physical condition of a 30 year old indefinitely then you are able to pull your own weight.

Do you think you could work for 200 years straight? I suspect that'd be disastrous to mental health. Society will need to figure out PTO under the new regime as well, or additional research will need to be undertaken just so our minds can keep up with our foerever-young bodies.

Those things are nice, but individually they each only have an expected value of maybe a couple of extra years of living time. Contrast that to curing ageing that would put that number in the hundreds or thousands.

Contrast that to mind uploads and humans become practically immortal with an infinite expected value - but I don't want the governments spending any money on that either at this point in time, before the human race addresses certain structural issues.

Honestly I'm not sure those numbers are compelling enough.

We, like, know how to solve some of those other problems. Sure, there's politics and bureaucracy and complications and the opportunity for corruption, but you can assign a p close to 1 we could get it done in an arbitrary timeframe.

Meanwhile, what's the probability that dumping a particular amount of money into aging is going to pay off? Even taking a thousand years you need a p>0.002 to make it worth diverting money from the safe bet of getting a couple of years off the other things.

Curing age related diseases is permanent fix, and makes curing any low hanging fruits trivial.