The problem is wildly more complex than typically portrayed.
First of all, there is a lot of work already going in to slowing and eliminating aging. Every "please don't smoke" campaign is actually a "smoking causes early death so not smoking prolongs life" campaign, if you think about it. Healthy eating, cancer prevention and treatment, dementia etc treatment and prevention, brain training, physical and mental rehabilitation training -> all are efforts to reduce odds of untimely death meaning all are efforts to expand life expectancy.
Outside of this, consider the magical curing of age related death tomorrow. Do people with unbearable conditions now have to live with them forever? With their quadrapligia, lack of long/short memory, parkinsons, etc? Suppose we can magic hand-wave our way around those.
What of births? Approximately 130-140 million children are born globally each year. That's another billion in ~8 years. We already struggle to feed our current population with ~700million facing food insecurity, and estimates say that using all available space, not wasting, and being more efficient with our diets we could perhaps support 20 billion on this planet. This would, however, require perfect cooperation between everyone on earth deciding to share perfectly and agree to move to plant based diets where required. At current birth rate, we'd have less than 100 years to solve food waste and build out the capacity. Or is birth now controlled a la China? Who gets to decide? What happens when the decision turns out to be wrong and leads to inbalance of viable mating pairs? Do we pivot to global sterilization? No more births until we colonize Mars?
And where does everyone live? If we are maximizing use of arable lands, humans can then only live in un-arable lands because we need farms and greenhouses on those lands. So we have to live above the green-line on mountains, tundras and permanent ice, and deserts. And the more food we have to grow, the less land we have to live in, meaning density increases meaning that the odds of a super-spreader disease increases meaning that people will die regardless because in all of this we never cured death but only age-related death.
>And when I look at the problem... it seems entirely solvable!
If that were the case, that you really saw a clear path, you'd write the proposals and get the funding. If it is the case, rather, that what you have is simplistic hope/belief that it "should" be solveable, then you're in the same boat as everyone already doing the research, minus any actual research contribution.