All of that lead exposure likely pales in comparison to what was happening driving in a car with windows down (when AC wasn't common) and all the cars around you were burning leaded gas with zero emissions control equipment like catalytic converters. You were just getting blasted by air full of lead and other combustion products.
The reason to prefer lead-free solder is primarily because at industrial scale with tons of trashed electronics the lead becomes an environmental pollutant. For hobbyists, lead solder is easier to work with, and not a serious risk.
I've got ventilation going much stronger now.
The only thing I am noticing that's left in my argument is that there are also bad chemicals that can be detected by human olfactory sense. My original point was that "Just because it has no smell, doesn't mean it is good for you", which is perfectly congruent and abdicates the fallacy you've listed.
And their point was that that being true doesn't make the comment you replied to "bad advice" as you claimed.
I can find these kinds of kits online from the 60’s but they all claim to be lead free. I wish I could find one of the original kits he had growing up.
(e.g. lead toxicity is well known since many centuries)