There are two issues to think about. One is that diagnoses don't mean much. If you get a diagnosis of chronic lyme disease, it does not mean that is suddenly a real disease, and life expectancy is basically meaningless.
Diagnoses and even medication prescriptions are not the same as diseases. We diagnose more diseases earlier and better than in the past and America accounts for 80 percent of worldwide drug spending. That doesn't mean Americans are really more ill, it means they get more diagnoses and medicine - everything from a chronic lyme disease to gluten sensitivity diagnosis can be yours if you try enough. We are so great about caring for health there is hardly a person in the country without some medical diagnosis and we're going to have up to 50 percent more senior citizens by 2050 - all living healthier and better than ever.
People may be told they have more risk factors, because knowledge of medicine is improved and epidemiology can link anything to anything at this point, but that does not mean people are dying off sooner than in the past. Risk is a poorly understood concept now, thanks to Harvard School of Public Health using surveys to claim there are "miracle foods" with statistical significance while activist epidemiologists claim trace chemicals can be linked to all kinds of worse outcomes if you unscientifically ignore dose.
People get more prescriptions due to more talk about risk factors - look at any TV program and count the ads for medication for increasingly obscure risks - but just like lowering the poverty level so that politicians can claim they 'lifted' poor people out of poverty before this next election, it does not mean anything real.
Most know by now that "life expectancy" is a scientific red herring. Life expectancy is the demography equivalent to Body Mass Index, useful for population level looks at trends but meaningless in health care. Life expectancy went down due to COVID-19 but that does not mean people are less healthy than they were during the 1950s Asian Flu.
Life expectancy is instead most often used for grift, like groups advocating for more money. And they use bad statistics to advance their cause. A country like Cuba, for example, is lauded for its life expectancy by people in the US who want more money for their cause but actual Cuban health care is terrible. The reason they have decent life expectancy is because any fetus with a serious issue is aborted, but in America doctors fight for every child if a woman chooses to have it, even if they will only live a week after being born. If a child lasts to the age of 5, life expectancy is not only high in the US, it is higher than ever. On the other end of life, thanks to smoking cessation and harm reduction efforts, the US is far ahead of Europe and Asia when it comes to fewer chronic illnesses due to smoking.
The big problem looming for the future is obesity, which will soon overtake smoking as the leading lifestyle problem. But poor people being able to afford food is a much better problem to have than starvation. It is entirely solved by cultural maturity, we need to grow beyond 'we don't know when our next meal will be' thinking, no regulations or authoritarian preaching needed. And that is a much easier problem to solve than nature constantly wanting to kill us with diseases.