TBH I'm not sure where I'm getting the 2.5% number from; it's the one that stuck in my memory from the last time I dug into this data. It's entirely possible that my memory is wrong or the data I was looking at represented an outlier in flu deaths.

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.

Yeah, 1 - 1.5% seems inline with most data. That is: about 1.5% of all deaths are deaths from flu.

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)