I expect a lot of it is that manufacturers want to sell easy to install devices. Batteries are a lot simpler than wires. For something like a door lock, having

I expect a lot of it is that manufacturers want to sell easy to install devices. Batteries are a lot simpler than wires. For something like a door lock, having everything on the lock also makes the integration really easy. Solenoid type electrified levers more or less don't exist as residential products, even though that seems to be the way to end up with a nice looking installation.