We have been trying since medicine existed. Granted we can see much further now thanks to modern knowledge and tools, but we still can't see far enough to identify the causes or even speculate about actual solutions to aging. For all our technology and medical knowledge, getting somebody to live past 100 is still 95% a mix of genetic lottery and the chance of not developing too serious of cancer until really late.

The vast majority of medical spending is on treatment of illness/problems and always has. Very little money is spent on actually understanding and figuring how to pause aging itself.