The problem is that Wikipedia editors require "published" references, which typically means "published on paper"
What Wikipedia guideline page says that? The page I see says "The term published is most commonly associated with text materials, either in traditional printed format or online."
For the best results, homeschool.
There are plenty of countries where you can be thrown in prison for doing that to your kids. Germany is among them.
Your city's stoplights are balanced for a different speed.
Or they are balanced for the same speed in a different direction. On a two-way street whose signals are timed for 30 mph eastbound at a particular part of the day, westbound traffic is going to have a problem.
Or perhaps they are balanced for a different speed, the speed of the type of vehicle driven by the majority. Most signals are timed for people who drive cars, which means cyclists tend to hit more reds.
Notability on Wikipedia requires a non-dedicated source to notice it.
Where does that appear in policy? All I see is "independent of the subject". In your example, so long as Fountain Pen has developed a reputation for fact-checking in the field of fountain pens, and Fountain Pen's publisher isn't owned by the maker of Nemosine's pens, this counts as an independent reliable source. Two more of those and you have notability.
it's a fountain pen magazine; it's dedicated to the topic, thus not notable.
I haven't seen that. Articles in scholarly journals and in other specialist periodicals get cited all the time.
the person from a century ago might not be as notable to people today
That's not how it works. Something becomes notable when unaffiliated reliable sources have covered it. This notability, if established, does not decrease over time. Such a decrease would require the existing reliable sources to stop existing. The reason Wikipedia has a notability requirement in the first place is that an article about a non-notable subject has no reliable sources that it can cite about anything.
"Gravitation cannot be held responsible for people falling in love." -- Albert Einstein