Speaking as one who ought to have retired, but is still working: living to 120 is only worthwhile if you are in good health. Few people make the century without being bedridden or mentally vacuous or both, but let us assume that this becomes medically possible. The next question: old age for everybody, or just the fat cats who can afford the new super-medicine? If we are democratic and everybody can have an enhanced lifespan, there is still the little problem that some people don’t get that old anyway, and generally it’s a family thing, aka genetics. So maybe our “Methuselah for all” system has to include genetic engineering, which is potentially a Pandora’s box on a huge scale.
So we all live longer and stay healthy longer, except for the self-destructive who ingest various substances that are fun but are not recommended for longevity. Now what?
The pension system, already overloaded, will have to be redesigned. We would be talking of people working until - until what? 85? 90? When retirement is measured in decades, you either need to save a lot in the first half of your life or the social security deductions skyrocket. This assumes of course that work is available, and the question is whether these oldies can do anything physical. Even to the extent of geriatric nursing, which many a person had to give up due to putting their back out, a lot of heavy lifting is required.
The extra life experience means that our super-oldies can offer a lot in fields such as teaching and counseling, and if they have saved some money in earlier years, they can do this sort of thing for low pay or none at all, maybe just to pass the time. And will that be the biggest problem? Somebody commented to me once that many pensioners spend their life going from meal to meal, punctuated by watching easy-watching programs on TV. You want 40 years of that?
Given that many jobs are automated away, what will these people do? Will they have work to pay for their extended retirement? Or will it be up to half a century of dreary poverty, maybe watching TV all day in a prison-like room in some built-to-a-price" subsidized housing apartment block? That would be enough to drive you to suicide, and curiously, suicide might well become a leading cause of death.That includes euthanasia and assisted suicide as well. Shoukd it be allowed when enough is enough, and nature won’t oblige for an interminably long time?
A big obstacle to a long life is the fact that the cells of the body tends to develop
faults when they reproduce themselves repeatealy, as they do over the course of our life, and the Big C is going to be a Big Problem. Cancer is already a major killer, because we are living longer.
That is the social side. What about politics? It could be interesting, as people have long memories and any politician would be constantly reminded of his past by an unkind electorate. Perhaps to the extent of “you’re just like your father / mother, and he / she was bad enough.” But while voters would know more of a politician’s history, it is does not follow that their voting patterns will avoid the election into office of totally unsuitable people. Older people can be very prejudiced - yes, I see a lot of that, and there is the fact that Trump, Hitler and Brexit got above-average levels of support from the wrinklies. Would an aging population be an intensely conservative population rooted in the status quo?
Wold an older population also be more concerned about the environment? If you have to live with the messes you made, longer than before, would you be more careful? And another issue; would you be more inclined to plant trees if you knew that you would live long enough to see them grow tall?
But, given the chance to live to 120 in good health, I would be all for it if I could be sure of a pension that is adequate to live on. Boredom? No problem, I have plenty to do, and can find more to occupy my mind.