[cameldrv]

I think it was a combination of things.

1. Inertia: Sanitizing and disinfection was what was recommended in March 2020. Even masking was actively discouraged until later.

2. "We have to do something." "This is something."

3. Handwashing/hand sanitizing and sanitizing surfaces are visible actions that reassure some people. Ventilation and filtration improvements are generally not visible.

4. Ventilation and filtration improvements are expensive and, for an institution, require certified professionals to design and implement. There aren't enough of these people and not enough equipment to implement this for every building in a timely manner. Handwashing and clorox wipes are cheap and anyone can use them.

Personally I think that COVID is likely going to be with us for some time to come and will cause significant disability as people get infected repeatedly. I think eventually we will see significant uptake of ventilation/filtration improvements.