An example. One niche, medium competition. Most of top spots taken by short posts / pages. Year 2019, two or three algo updates, and out of nowhere, top spots overtaken by other sites, most of them with long posts / pages. I'm not saying this was the only difference between the two types of sites, I don't know, otherwise I would be able to answer your question - at least for a particular niche. But here is something keeping my mind busy for some time now: maybe now, when on my bread and butter niche, everybody is having just long posts / pages, maybe is time to try a few short ones. I'll do that in the next couple of weeks, and see what's up