Here is a quote from the abstract of the paper linked above:
> Results: The inpatient group was composed of 343 patients, median age 65 yr: 206 men (601%, median age 66 years) and 137 women (39.9%, median age 65 years) with a rate of daily smokers of 4.4% (5.4% of men and 2.9% of women).The outpatient group was composed of 139 patients, median age 44 years: 62 men (44.6 %, median age 43 years, and 77 women (55.4 %, median age 44 years). The daily smokers rate was 5.3% (5.1% of men and 5.5 % of women). In the French population, the daily smokers rate was 25.4% (28.2% of men and 22.9% of women).
The average daily smoker rate is taken as-is over the whole population, and compared to the smoking rate of people of age around ~66 years, despite the article itself stating that the percentage of daily smokers is lower for old people and higher for young people.
So already in the abstract they have made a mistake and forgot to correct for age. I have not read the rest of the article in enough depth to judge fully, but I would absolutely not blindly trust researchers to always do this correction in an appropriate way.
If most people that have severe COVID complications and end up on the ICU are aged 80+, and generally smokers die before that age from smoking-related complications, doesn't it naturally follow that most people on the ICU will be non-smokers? Smoking will have killed the smokers before they become part of the high-risk group, after all.