One hour is typically my upper limit on long-form video essays, unless it's a complicated topic I'm interested in, or it's from a reputable source that I really really know is going to keep me entertained. For example, Folding Ideas' NFT video really did need the two hours to explain it in depth, and he does a really good job at long-form essays, anyway.
But, I really don't understand why some of these put out the 3-, 4-, 6-hour essays. To me, they just don't know how to edit down their material, because no topic needs to take that long to explain.
Probably a seasonal thing between months. Music and books seem to be on the rise here.