May I refer you to the 1859 Russian classic Oblomov -- "Oblomov is a young, generous nobleman who seems incapable of making important decisions or undertaking any significant actions. Throughout the novel he rarely leaves his room or bed. In the first 50 pages, he manages only to move from his bed to a chair."
https://en.wikipedia.org/wiki/Oblomov
Oblomov is more a treatise on 19th-century Russian nobility, but I find it interesting that lethargy and lack of direction has been democratized. :)
We used to have work and war to keep the youth busy. Now, in developed countries, we have...virtual work and war...video games. Part of me thinks that Japan got hit with this phenomenon earlier than the US because they were outlawed from having an army for the past 60 years.
I'm reading Blood Meridian for the second time now - I think I like it even more now than the first time.
Personally, I think if you're looking for a strong argument about a single direction for such a thematically complicated novel, you might look at Mavericks at the Border: The Early Southwest in Historical Fiction and Film.
Amazon link: https://www.amazon.com/Mavericks-Border-Southwest-Historical...
Orin, the main character's older brother, becomes a semi-recluse/sociopath, which is the closest character to an explicit Hikikomori DFW paints in the book. The other major characters rely on other forms of relief to cope with their anxiety, depression, family issues, etc.
DFW wrote Infinite Jest in 1996 before the internet truly took over. I'd love to see another book tackle the issues and repercussions of internet-soaked culture the way DFW tackled the nature of addiction in Infinite Jest.