The reaction to her earnest advice was rage.

“Wait, this is the good news?” read one indignant post on Twitter, echoing many others. Slate’s Jamelle Bouie called it “a great example of ‘we turned the economy into a miserable hellscape and you’re just going to have to deal with it.’”

Ouch. But Munnell assured young people that they don’t need to cancel their retirements entirely. “In fact, my research shows that the vast majority of millennials will be fine if they work to age 70,” she wrote for Politico. (Small solace given that life expectancy for Americans recently took a turn for the worse.)

Still, Munnell has a point. Across a generational time-frame, people are still living much longer than their parents. As my colleague Peter Coy recently pointed out, a man who is “chronologically” 65 is actually more like a 55-year-old from the perspective of 1957. With the extra years, a longer career doesn’t necessarily mean a shorter retirement.

Retirement-age Americans are already working in record numbers. Whether by choice or necessity, because of boredom or fear, a full third of those between 65 and 69 were in the workforce in May, according to the Bureau of Labor Statistics, along with 19 percent of those aged 70 to 74—together almost double the number 30 years ago.

Nevertheless, the retirement advice of “just work longer” can sound pretty tone deaf to younger ears, especially when the old American promises—of advancement, financial security and home ownership for everyone who works hard—have faded into myth.

What about the booming economy of 2018? Won’t that help smooth the path for young savers? Perhaps, but Goldman Sachs Group Inc. economists recently said the current pace of the U.S. economy is “probably as good as it gets.” That can only make young Americans more furious about the “missed opportunity” mentioned by the St. Louis Fed.

Paychecks aren’t reflecting the improving economy. Hourly wages were unchanged in May from a year earlier. And according to a Fed survey, four in 10 Americans said it would be tough to come up with $400 for an emergency expense. The same 2017 survey found 27 percent skipping medical treatments because they can’t afford them. Another poll this month reaffirmed the inability of many Americans to save any money at all.

So work longer? First you have to live longer, and that’s not guaranteed.

Wide swaths of the country are getting sicker and dying younger than just a few years ago, with a widening health gap between educated, affluent Americans and everyone else. Alcohol abuse and obesity, upticks in suicide and an epidemic of drug overdoses have all played a role in an ominous milestone: Year-over-year declines in American life expectancy while the rest of the world lives ever-longer.