There are many people with learning differences, e.g., dyslexia, who can greatly benefit from audiobooks. Learning Ally has quite a few of the merit badge handbooks on audio. There is an annual fee of Learning Ally is not part of the school's library. See: https://learningally.org/
This does seem like a systemic issue. You may wish to reach out to the scout and his family to see how they feel about the situation and what actions they want to undertake with your support. Additionally, you may wish to record instances of bullying by the CC to corroborate your claim of bullying when the CC is ultimately confronted.
I am doing what I can. I am a merit badge counselor, certified RSO, Rifle Instructor, and Shotgun Instructor. I will finish my ASM training this weekend. I have also been one of the adult members of a number of board of reviews.
Is it really a den without a leader?
I mean, at some point you're going to have to be pretty blatant about it.: Either someone steps up and into the DL role or there isn't a den.
It isn't fair to the leaders attempting to help out in the interim nor to the boys/roles they are supposed to be attending to. Let's face it, it's pretty obvious by now that as long as they don't NEED to, nobody will volunteer to be DL. Unfortunately you have to force their hand. Will it get you the optimum, an enthusiastic and committed leader? Probably not, but you don't have that currently, either.
If nobody does, disband the den and devote your resources to those that are willing to provide their time and effort. Maybe they'll come to their sense for the next year. Or better, before you have to dissolve their den.