Life expectancy at age 65 (LE@65) has been increasing about 1.5 years/decade since the 1980s. Articles have been written that "70 is the new 50" and similar themes. The reason is that medical advances are keeping seniors alive who would have died from the same illness a few decades ago.
The downside is that while many seniors are younger and more active than any previous generation, some will spend more years in declining health.
A decade ago, I helped one of the world's leading anti-aging scientists write a book on longevity, what causes aging, and what can we do about it in the future.
The problem is that aging is so multi-faceted that fixing one problem (heart damage, for example) only delays other inevitable problems... hardening of the arteries, Parkinson's, Alzheimer's, cancer, immune system declines, etc.
Medical science is getting much better at fixing aging organs, but the Holy Grail of antiaging medicine is reversing aging at the cellular level so these illnesses don't occur in the first place.
I believe that most high schoolers reading this will have a LE@65 of 100 or so, providing that they don't destroy their bodies from obesity and sedentary lifestyles. Even with the primitive anti-aging approaches we have access to today, most 50-year-olds today could reach my age 75 as healthy as me if they just made achieving optimal health a top priority in their lives. Most people do just the opposite... they ignore their health until something bad happens. That's like ignoring oil changes until your car's engine breaks and then trying to fix it.