Even if I take those numbers at face value, it's disengenuous to mix in those from 1964 and up until we banned public smoking nearly everywhere you can imagine. The last place you can smoke freely is your home, and this doesn't address that.

Honestly the secondhand smoke research is very sketchy. Actually anything that becomes a public health issue ends up getting distorted by the public health establishment. Case in point: flu vaccines. They’re so ineffective that no rational person would ever waste time taking them, yet many of us do: https://www.cochrane.org/CD001269/ARI_vaccines-prevent-influ... (note: the “no rational person” is slight hyperbole)

The better argument is that the actual social behavior of smoking is contagious, as any social behavior is.

The victims of secondhand smoke aren't someone standing on the street next to a smoker but people (and pets) who grow up in a household with smokers. Whether or not the numbers are what they are claimed to be it's hard to argue against the reality that thousands of children are subjected to the very real harms of secondhand smoke their entire childhood with no recourse, especially when they are most vulnerable.

I don't say this to say we should ban tobacco because "think of the children" but I genuinely think people seriously overlook this aspect. Someone smoking near you as an adult might be obnoxious but children in smoking households suffer and develop lifelong health problems for a vice that is entirely out of their control that many people don't even really see as a problem or think about.