Of all the ways I’ve logged books, I’m thinking that plain text remains the best. I’ve been adding books to a text (Markdown) file for while now and it’s not pretty, but it works. And it will always work.
I publish a copy at https://www.baty.net/books.
Like I said, it ain’t pretty. On the other hand, I use it regularly by simply running little searches. If I want to know how many books are read in 2020, it’s just grep 2020- books.md | wc -l and I get 14. To see the actual books, it’s even easier: grep 2020- books.md which gives me this:
- A Gentle Madness: Bibliophiles, Bibliomanes, and the Eternal Passion for Books by Nicholas A. Basbanes (2020-01-05) | ★★★★
 - How to Do Nothing by Jenny Odell (2020-02-05) | ★★
 - The Instructions by Adam Levin (2020-02-15) | ★★★★
 - The Wisdom of Insecurity by Alan W. Watts (2020-03-06) | ★★
 - American Dirt by Jeanine Cummins (2020-03-09) | ★
 - Recursion by Black Crouch (2020-04-05) | ★★★
 - Devoted by Dean Koontz (2020-04-23) | ★★★
 - The Soul of an Entrepreneur by David Sax (2020-05-04) | ★★★
 - Shakespeare for Squirrels by Christopher Moore (2020-06-09) | ★★★
 - Network Effect (The Murderbot Diaries, #5) by Martha Wells (2020-06-24) | ★★★★
 - Dark Matter by Blake Crouch (2020-07-19) | ★★★★
 - The Permanent Portfolio by Craig Rowland (2020-07-22) | ★★★
 - More Effective Agile by Steve McConnell (2020-10-10) | ★★★
 - Futuristic Violence and Fancy Suits (Zoey Ashe, #1) by David Wong (2020-12-27) | ★★★★
 
Or, how many books have I read by Christopher Moore? grep 'Christopher Moore' books.md:
- Coyote Blue by Christopher Moore (1999-01-01)
 - The Lust Lizard of Melancholy Cove by Christopher Moore (1999-01-01)
 - The Griff: A Graphic Novel by Christopher Moore (1999-01-01)
 - Lamb: The Gospel According to Biff, Christ’s Childhood Pal by Christopher Moore (2008-12-24)
 - Island of the Sequined Love Nun by Christopher Moore (2009-03-12)
 - A Dirty Job by Christopher Moore (2010-12-28)
 - Bloodsucking Fiends by Christopher Moore (2010-12-28)
 - The Stupidest Angel by Christopher Moore (2011-01-01)
 - Secondhand Souls by Christopher Moore (2015-11-12)
 - Noir by Christopher Moore (2018-05-15)
 - Shakespeare for Squirrels by Christopher Moore (2020-06-09) | ★★★
 
It’s not perfect, and leaves out any kind of social discovery, so I also enter books in both GoodReads and StoryGraph, which honestly only takes a few minutes per book so it’s hardly a burden.
I love that my plain text book log is so lightweight and simple.