Sort of interesting, but the whole setup is oddly misleading: "Smoking and firearms are among the leading causes of avoidable premature death in the United States" The statement is true for smoking but it takes some work to make it true for firearms. And then it describes tobacco and firearms as "both are legal yet lethal" - it borders on nonsensical to pair them that way (I guess possessing both can be legal, but it…
I think the paper is purely political. Alcohol causes 140k deaths per year, and if there were any scientific goal here they would have included alcohol before including firearms.
Alcohol related non-drinker fatalities would be the relevant measure (and still too many, since it's going to be drink driving largely).