I thought we read an article (on one of latest CV threads) that said the opposite.
It compared the measures taken between Philly and St Louis...who both had first cases of 1918 epidemic about the same time....
Philly continued on with public gatherings, school openings, etc., while SL stopped all public gatherings, closed schools. The difference in deaths, betweet Ph and SL were about half (Philly having twice as many deaths, than SL).
The measures taken, by SL, were attributed to a doctor who also headed up their health department.
Our theoretical analysis demonstrates that, in the cities that saw double-peaked autumn epidemics, control measures may have been, if anything, too effective, stopping transmission so effectively that substantial numbers of susceptible individuals remained in the population when controls were lifted. This remaining susceptible pool allowed transmission to restart, leading to another epidemic peak and (in some cases) to the resumption of interventions. Conversely, cities in which transmission had been continuing for longer before interventions were introduced saw much smaller or no second epidemic peaks, because insufficient susceptible people remained to restart transmission. The theory of imperfect interventions tells us there is an optimal middle ground, i.e., interventions tuned to give a single peak of minimal size.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1849868/
We don’t need n-95 masks.