If you look at the global numbers not all countries had a similar drop in life expentency (ie. Denmark and New Zealand had no drop) but went through similar or more severe lockdown and vaccine policies.
https://www.cdc.gov/nchs/pressroom/nchs_press_releases/2021/...
Blaming life expectancy drop on "undetected" covid without any evidence is not very scientific. I can say it's undetected drug overdoses too.
Maybe either root the logic in facts, or don't write off alternative possibilities.