Although a good pâtissier (pastry chef) or a restaurant chef always has a collection of these little gems in their kitchen drawer, it is surprisingly rather rare to see one in the everyday household.  What you could be missing is no less than:

Filling your plate for no extra cost

Have less bits and pieces of food in your washing water

Reduce your fat intake by using less oil when you sauté meat, fish, or eggs; you can even directly brush pieces of meat with oil instead of brushing the pan.

Avoid touching food with your fingers when you even out the surface of your dish.

Imagine:

Get that last bit of shredded carrot

Bring back that last grain of rice from a saucepan or a pan

Fill a teaspoon with cakecrumbs instead of kissing them goodbye on their way to the bin

You could even have a dedicated brush to dust your computer keyboard or your spectacle lenses.

Naturally you will have a collection of brushes with different widths as opposed to a single one.  Some will be reserved for fat matters, and others for dry ones.  Avoiding using the oil brush to dust your lenses may be a good idea too for example!

To ensure a win-win contract with brushes, you will need to keep them thoroughly clean and dry.  Their hairy heads like to hold onto oil droplets and water, and will take a while to dry.
After you’ve used them to collect the last crumbs of your dishes and pans, plunge them into your washing water as soon as possible, to allow them to soak in hot soapy water.  This will help make them less oily, dry faster, and keep them bacteria free.  Only put them away in the drawer when completely dry.

For a handful of dollars, have a crush on the foodbrush.