Those metrics imply that what images are being used is completely irrelevant. Either that's true, and we could all just use the same photo everywhere (I suggest the one of St. IGNUcious, Your Mileage May Obviously Not Vary - all hail the irrefutable and infallible 2.3x metrics!) or it could still be true that a "super generic stock photo at the beginning of an article" is, indeed, pointless.
> Blog posts with images get 2.3x more engagement