Most people don't die every year; 2.5% [well, 1.5% last year] of the people who die, die of the flu.
US population: 330M
Deaths per year (approx): 3.46M (call it 1% of the population)
2.5% of deaths: 86,500 people
Number of flu infections, per year: 9M .. 41M
2.5% chance of dying of flu: 225,000 .. 1,025,000 people
Number of deaths due to flu, per year: 4,900 .. 51,000
Actual chance of dying of flu (2010-2022): 0.01% - 0.5% [0]
[0] min ((4900/41000000), 4900/9000000)) .. max (51000/41000000, 51000/9000000)
> the IFR of the seasonal flu is around 0.1%
We're all going to die some day. Based on current causes of death, there's a 20% chance, give or take, that it will be heart disease. A 20% chance it will be cancer. A 2% chance one of us will die from kidney failure. And around a 1.5% chance it will be from the seasonal flu, which has an IFR of 0.1% or less.
Anyway, bringing this back around to the Spanish flu, it's fascinating, to me, that if you were alive in 1918, there was around a 1% chance you would die, that year, of the Spanish flu, and around a 2% chance you would die, years or decades later, of a seasonal flu. Pandemics get you upfront, all at once, epidemics get us eventually, over time.
"If you die, then the cause of death is to 2.5% the flu" is one meaning. Likely close to correct.
"With 2.5% you will die this year a death caused by the flu" is another. Unlikely to be correct.
For the 2023 / 1.5%, I referred to the provisional vital statistics for 2023: https://wonder.cdc.gov/controller/datarequest/D176;jsessioni...
Looking at past years (https://www.cdc.gov/nchs/data/databriefs/db355_tables-508.pd...), I get more like 2%, even for bad flu years like 2018. So that 2.5% number is probably either completely misremembered or based on provisional data that has since been revised downward.
However, deaths among those infected by flu are much, much smaller than this (because the number infected is much, much bigger than the total number of deaths)
I don't think anyone dies every year. Just once. /s