If all this feels a bit sad it's because it is.
What I love about Kavita is that it seems to be much more social because I can lend books to a friend. I haven't checked if this is supported but the killer feature for me (for which I'd adjust my above rules/behavior and switch to Kavita) would be collaborative reading where we can put books on each others reading list, share notes or comments, or view each others progress. Like Netflix guest accounts with the difference that you can actually do things together (so way beyond Netflix today)
The "sharing" sounds a bit intrusive but it would help me a great deal in keeping up with my daily reading goals knowing that it's public to friends. It would be cool for book clubs too. Kavita is the first software where such features would/could make sense (if not then maybe in a fork?)
Right now I convert all my formats (epub etc) into pdf and then after disabling my network, use zathura with a dark theme to read. I keep notes with markdown files and once I've finished the book I reneame the pdf from book_title to read-book_title. Reading it a second time the filename becomes read2-book_title and so on ... When I share a book I send the file to a friend (only if they ask) who put it on their reading list and (10/10) forget about it forever.
It's a dumb approach for single user where the goal is to read as much as I did as a child without distraction. It's actually worse an experience than having the physical book in my hand which I can smell and then put on a shelf like a trophy and be proud of or lend it to a friend who will only ask for it if genuinely curious because they know once they return it they probably need to say a word or 3 about what they thought of it (or admit they didn't read it). With digital books I often finish a book and still don't know the author because the only time I've seen the cover was when I was at page one. And even the title I forget quickly regardless how good it was because of the same reason.
Kavita makes me a tiny bit excited, ... if not about it's current state, then about the potential it could have.