We know (from RKI) that 86% of the fatalities in german ICUs were people with an age of larger than 70. Compare that to the distribution of smokers vs age in germany. 80% of the smokers are younger than 70.
https://upload.wikimedia.org/wikipedia/commons/1/16/Percenta...
https://www.rki.de/DE/Content/InfAZ/N/Neuartiges_Coronavirus...