As parents, it’s your job to ensure that your children grow up to be independent, functional members of society. To do this, you need to train them at an early age. For instance, when they’re three years old, have them do simple things, like putting their clothes in the hamper basket, or fetching a beer in the fridge.
Asking them to open a banana for you is alright, too, but remember that they don’t have your level of dexterity. It’ll take them weeks, if not months, to finally unpeel a banana, after which it’ll already be brown and bruised. Maybe just stick to the fetch-daddy-a-beer-in-the-fridge thing for the time being.