No! Most likely the reason why you didn’t bother to read the piece was not that it was too long but that it was too boring.
People have no issue with longform if they give a damn. People binge watch 5 episodes of Game of Thrones in a row and read books until late in the night. While skipping tweets and TikTok reels.
If someone has an issue sticking with a piece of communication, length is most likely not the issue.
It’s much more likely that either this piece is just not for you or that the creator of that piece didn’t care enough about who gives a damn and why.
So, for you: Who? And why?
And when it’s me, then draw me in. Step by step – at each step giving me a reason to care for this step.