The engineers at Google do know how our algorithmic systems work because they write them. And the engineers I work with at Google looking at the article about this found it strange anyone believes this. It's not our advice. We don't somehow add up all the "old" pages on a site to decide a site is too "old" to rank. There's plenty of "old" content that ranks; plenty of sites that have "old" content that rank. If you or anyone wants our advice on what we do look for, this is a good starting page: https://developers.google.com/search/docs/fundamentals/creat...
There is. Which is why I specifically talked only about writing for algorithmic systems. Machine learning systems are different, and not everyone fully understands how they work, only that they do and can be influenced.