I don't see why people are complaining about the UI. The calibre codebase is just Python and you can vibe code/customize a nicer UI for it in minutes. It's not like the core changes much. Their metadata resolution and Epub handling and (formerly DRM cracking) are best in class.
Can we please stop with the suggesting vibe coding for everything? It’s not an interesting response: it doesn’t advance the discussion and no one learns anything. The goal of this website is (ostensibly) intellectual curiosity, and suggesting AI as a solution to every problem is basically a thought-terminating cliché.
Vibe-coded or not, I prefer staying close to upstream unless I have very good reasons not to, and I would not want to have to half-heartedly maintain a UI fork of this. I would still be quite excited about an official visual overhaul, though