Many reasons:

• localStorage only works in the browser process.
• localStorage is not very fault tolerant, so if your app encounters an error and quits unexpectedly, you could lose the data.
• localStorage only supports persisting strings. This module supports any JSON supported type.
• The API of this module is much nicer. You can set and get nested properties. You can set default initial config.

okay nice!!

I suggests to copy this list to the readme.md

IMO，localStorage is not very safe, it may be leak through xss attack.

Another advantage is subscriptions!

It's also worth noting that localStorage and indexedDb data can be lost if a user installs an older version of your app which uses an older version of Electron.

Chromium only caters for upgrades to the underlying levelDb store. If you run a previous version of Electron, it can fail to read the levelDb store and deletes it to start again from scratch!