I tend to disagree. I have reliable sources giving the date of birth and death of my great-(x many) grandparents, as well as a few other facts of their lifes. Does that make them notable?

Sure, but no published source in which your grandparent is featured.

I think the internet archive is a reliable source on the content of webpages. Does that mean every webpage on the internet archive is notable enough to get an article on Wikipedia? Every separate game of chess that has its notation published? Lab rat #2687?

I think there is a difference between mentioning something trivially, and an article featuring something. There could be featured chess games, which is different from a mere mention.

Regards, Ian Tresman