The Speculist has a clear article and graph that explains how curing all diseases (other than aging) compares to curing aging in terms of life expectancy. This is simplified.
If we cure all diseases (all diseases, that is, except aging itself) 20% will make it to 95. So if you're part of that lucky 1 in 5, curing all disease would give you only 10 years more than you would have had in 1960.
The graph assumes that we don't ever get any better at avoiding accidents or violent incident - but at least 80% of us would make it to age 250. 20% would live 1000 years or more.
Aubrey de Grey and Chris Phoenix worked out various graphs based on how old someone is when effective anti-aging therapy is developed and the constant need for ever improving rejuvenation treatments.
The de Grey/ Phoenix model predicts that, if progress in eliminating successive types of damage continues at a sufficient pace (which, we stress, is a pace very typical of past technologies – prominent examples include powered flight, computers and the combating of infectious diseases), the amount of damage present in the body can be kept low, with a negligible rate of age-related death per year, irrespective of a person’s age.
Your Chances for Extreme Longevity Depend Age when the First in a Series of Rejuvenation Treatments Arrive
How long could you live and the odds depend on when major rejuvenation technology starts.
If you are 50 when SENS 1.0 arrives then you have better than even odds of living hundreds of years.
If you are 70 when SENS 1.0 arrives then you 10% chance of living hundreds of years.
If you are 80 when SENS 1.0 arrives then most likely you might a few extra years and then die as the current normal situation.
The gap between better aging treatments and the quality of the treatments also is a factor. The above graph assumes aging mechanisms are halved every 40 years. If the aging mechanisms are halved at a faster pace then more people will live longer. If aging mechanisms are more than halved then more people will live. If the treatments are less effective and take longer to develop then more people will die.
Vaccines to eliminate extracellular aggregates (especially amyloid which is a big part of Alzheimers) seems likely to be deployed soon
Aubrey de Grey think there's a 50% chance of getting the first-generation SENS [life extension] therapies working within 25-30 years.
Stem cells could provide unlimited disease free blood and significant rejuvenation therapies.
Calorie Restriction mimicking drug could be available in five years and provide a 3-13 year boost in life expectancy.
De-aging livers and preventing cellular aging makes progress.