Or increasingly, a library written by an LLM referencing a pile of such “one guy” projects of varying levels of suck (from actually good to good-got-it-is-full-of-suck).
What I have been seeing recently is having a great LLM rewrite the library leads to fewer bugs and also optimized for your use case. More expensive for sure than pulling something like epub.js but when the library has infinite open issues it can be a lot better.