Haven't seen these links mentioned elsewhere in this thread, but in case you haven't seen them yet:

* SQLite is 35% Faster Than The Filesystem [1]

* Writing to files safely is hard [2], and SQLite goes to great details to ensure consistency in case of application, OS, or computer crash [3]

[1]: https://sqlite.org/fasterthanfs.html

[2]: https://danluu.com/deconstruct-files/

[3]: https://sqlite.org/atomiccommit.html