https://bugs.openldap.org/show_bug.cgi?id=10066
--- Comment #2 from christophersauer@pacbell.net --- I did a bunch more reading, and the plot thickens a bit. It sounds like SQLite added it long ago at Apple's request but then Apple decided to not use it themselves, because there's such a heavy performance impact. (Source: Hipp's comment here: https://bugzilla.mozilla.org/show_bug.cgi?id=431863) Further, there's no way to turn it on in Apple-bundled SQLite (https://bonsaidb.io/blog/acid-on-apple/). mdbx does have it on by default, with an option to disable.
I think it's murky enough that we probably don't do it, following Apple's actions rather than their docs? But I should instead be drawing on your much greater database expertise. Is it indeed true what people say: that most drives lie about fsync anyway, that this stuff doesn't matter that much, and that people mostly just prefer the speed? Seems like a strange world where no one actually gets the guarantees they talk about...