How essential are we talking about here?
What I mean is, your smartphone is a device that can get lost, stolen or destroyed any day. All the data that is physically stored in it should either be expendable or synced elsewhere.
Are people creating new contacts that often on a phone? I probably do that only a few times per week. If the phone crashed immediately following the input, I'd just ask the person for their details again.
> corrupt an essential database?
It would only corrupt application data. Android isn't completely stupid, /system is mounted read-only on every Android phone I've ever seen.
I guess it depends on how highly you depend on application data remaining consistent.
Presumably the corruption would only apply to data that was modified but had not been flushed to flash before the power cycle, so at rest data shouldn't be affected.
> I probably do that only a few times per week.
If your data is kept in a SQLite database or any other type of compound storage scheme it's entirely possible to lose data that wasn't being modified, due to corruption of the metadata that governs the layout of the file (actually I don't have experience with SQLite file format specifically, but I ruined my startup's launch a decade ago with almost identical reasoning--thousands of pressed CD-ROMs in the garbage).
Do you just lose a new contact, or corrupt an essential database?