The takeaway should be:

Don't assume sqlite is doing an fsync on each commit.

While that's the "default default", you may be using a sqlite3 compiled by someone else or using non-default build options, or using a wrapper that sets its own defaults.

More generally, be careful about assuming any of the various levers sqlite3 has are set in a specific way. That is, take control of the ones that are important to your use case (well, and before that, review the levers so you know which ones those are).