The source – youtube.com
A recent video meeting for webmasters clarified the question of E-A-T as a ranking factor.
Google employee John Mueller responded that these factors – expertise, credibility, reliability – can affect rankings, but not directly.
If Google took the time to put information about E-A-T in the Assessor's Guide, it's important to the work of search quality professionals who work on ranking algorithms.
But Mueller clarified that Google doesn't have such a numerical indicator as E-A-T. The factor has to do with "understanding the context of content online," which can be considered a pretty complex area.