For example: "age of the article": search engines value recent content => suddenly you start seeing articles published just weeks/months ago reviewing some rather old piece of hardware/content. Either a full repost under a different URL with a different title etc., or just an incremental (probably automated) update of an older page.
If I crawl your site today, encounter article A, and crawl it again in a year and again encounter article A, I am sure that article A is a year old (Well, techcnically, what I am certain of, is that I encountered the exact same article two times a year apart). You cannot game that. Now if another year later I encounter article A' where some content on the page has changed, be it sidebars, a new design, or a few paragraphs, I might say, "some version of this article is two years old" and decide to rank that different from "this exact version is two years old".
Age is just one variable that I can think off. I'm quite certain there are more variables. But each and every one such variable must be completely controlled and verified by me- the search engine. Nothing external can be such a variable: not "amount of articles that link to X" nor "amount of people that click through".
Maybe such variables don't exist. Or maybe they do, but make for terrible ranking, IDK. But I do know that using variables that search-engines don't control make for a terrible search experience over time. As can be witnessed and as is written down in the linked article.
It's not as if SEO types have time machines?
And what if I change a tiny amount of the article, or post it on a second domain I own? Do you think you can match up all the near duplicates at the scale of the internet?
I also don't think this makes sense on a fundamental level, if I write some excellent content it shouldn't be harder to find because I wrote it recently. We would be making it harder for new entrants and encouraging people to rush out low quality content/ even report on things before they happen and delete the incorrect guesses later (not that the current system isn't full of perverse incentives.)