What it's doing right now, or what it does habitually, or what it can do, or something else? Is the purpose of my toaster to sit there broken, because it's broken right now? This isn't very useful by itself imo.

> Is the purpose of my toaster to sit there broken, because it's broken right now?

This is proof by demonstration that for you, the highest value the toaster can provide, net of costs, is to be a room ornament.

I hope you are keeping its exterior clean.

Edit: Perhaps its purpose is to be a 21st century memento mori?