Yes, when game consoles are smaller, or people suggest consoles come with built-in batteries for gaming where power is not easily available like camping, or to play your console on other countries with different sized and shaped power plug sockets which don't work with US Power plugs.
A Built-in battery is also useful for playing your games during a power outage with a powered TV, or to save your game, and not lose your game save during a power outage.
A Built-in battery is also useful for playing your games during a power outage with a powered TV, or to save your game, and not lose your game save during a power outage.