I heavily use Zettelkasten combined with Emacs + Org Roam, it worked for me as I often want to link a wide range of information gathered through books, articles, etc, all the while being able to cite sources with bibtex and even generate diagrams and LaTeX equations on the fly.
I even wrote about it a couple months ago.
https://news.ycombinator.com/item?id=42560889