> but power failures are basically a non existent threat anyways

Not in the contexts sqlite3 is often used. Remember, this is an embedded database, not a fat MySQL server sitting in a comfy datacenter with redundant power backups, RAID 6 and AC regulated to the millidegree. More like embedded systems with unreliable or no power backup. Like Curl, you can find it in unexpected places.

I think in that context, durability is even less expected.