The risk of death per year increasing with number of years lived is aging.

Without that people have lived longer are more likely to have lower risks of death per year. And thus older people in such a society would on average live longer.

Unless it also cures cancer a more likely outcome is that people who get the treatment will just stay young until they get cancer and die. Also, as I understand it cancer also slows down in old age, so staying younger could mean faster cancers possibly negating some of the gains from the decreased aging.

Aging is more than just looking old.

If someone has an increased risk of death per year from cancer or whatever because something is failing over time they are still aging.

If the rate per year stays the same IE being 20 or 20,000 has no impact on your risks of cancer each year then someone that’s 20,000 likely takes very few other risks and is more likely to live another 20,000 years than the random 20 year old.

Cancer is primarily caused by aging, so in this world there likely wouldn’t be much cancer outside of the deliberate cancers caused by things like smoking

This is grossly wrong. "anti-aging" treatments won't reduce people's ages and won't undo epigenetic damage. And while age is the single strongest risk factor for cancer, it isn't the "primary cause", and there are numerous non-age-related causes of cancer.

Bad “anti-aging” treatments definitely won’t do it, but they also won’t provide indefinite lifespans.

> it isn't the "primary cause

Only if you’re using an inaccurate definition of aging. If everyone over 20 should have the same risk of cancer as 20 years olds the total number of cancers would drop by more than half.

P.S. The response is incoherent. Talk about "inaccurate definition" ... someone has an inaccurate definition of "cause".

Most of humanity will die in this century as a consequence of global warming, a subject that barely gets a mention at this site. There was a window of hope, but the Trump administration's policies have closed it.