So tell me, what is an authoritative source of factoids?

I like Quora. Encyclopedia's on print stock used to be the gold standard due to professional fact-checkers, Wikipedia is NOT an alternative to that medium IMHO. BTW, I did not know of the definition of Factoid — Had thought it was slang for Fact.

factoid: A piece of unverified or inaccurate information that is presented in the press as factual, often as part of a publicity effort, and that is then accepted as true because of frequent repetition.

Actually, this is strictly an American definition. In original English, (Cambridge Dictionary) it means what I used it for: FACTOID | English meaning—Cambridge Dictionary I'm Canadian, and we use/follow the King's English! July 19, 2023 — FACTOID definition: 1. an interesting piece of information, 2. an interesting piece of information. https://dictionary.cambridge.org/dictionary/english/factoid