I don't usually read lengthy contents unless I learn something new from them . Honestly, I have no time. A lot of so called lengthy contents, to me, appear repetitive and boring.
I prefer short and engaging contents over lengthy 'hard to read' ones. Quality is subjective so 'short' doesn't mean 'trash'. But I agree there is a lot of trash out there.
That is the trick. I have answered above explaining why long-form stands out. Anyone reading it gets sucked into it and walks away with something interesting.