If you're operating on these kind of statistics I think you need to consider the age and race of your child. If you go by likelihood of death, a 19 year old black male (covered by the chart you cited) has a wildly different chance of firearms related death than a 4 year old white child (for that child, they're more likely to die by swimming pool) [0]. In fact the choice to include 18 and 19 year olds at prime age for gang related violence on a study on a decision on what to do with younger children is in fact either a naive or intentionally biased approach.
Under teenage years, your kid is much more likely to die by assault by firearm than by suicide/accident by firearm [1]. It is not easier to fight off an assault while you are unarmed.
Under age 5, by your rationale you probably also never went to a house or anywhere else with a swimming pool, which at that age is as likely to kill your child as a gun. Operating based on this, a good case could be made a household without teenagers may be safer with a gun (assuming you are the owner and you don't assault children, and you either store the firearm on your person or secured in a safe) for protection against assault, while those with teenagers have to counter the risk of suicide by either not owning a gun or putting it in a secure safe. But then again, teenagers are still yet more likely to die by (firearm) assault than (firearm) suicide, so perhaps even they are better off if their guardian can defend them against armed assailants.
As a final note, assuming you do actually take your children places: your hosts probably lied. Not all of them did, but a few probably did, especially if you left the Bay area. Even the ones that are 'honest.' They knew that you would be uncomfortable about firearms in the house, and they themselves would be uncomfortable if their friend found out, so they simply locked them up somewhere in their house where they would never be found or could be accessed and then told you there weren't any there. I don't have the study off hand, but a well researched study I came across showed only ~30% of people truthfully inform guests with children about guns in their house.
[0] https://www.nejm.org/doi/suppl/10.1056/NEJMc2201761/suppl_fi...
[1]https://injuryfacts.nsc.org/home-and-community/safety-topics...