Apple TV for Remote Home Hub Control
Is the Apple TV with Ethernet (and 128GB) required for remotely controlling your HomeKit accessories? Or can this also be done with the Wi-Fi only Apple TV (64GB)?
Some people use Ethernet but HomeKit seems to prefer everything being connected to the same home wifi network. I would go with the latter.
See: Set up your HomePod, HomePod mini, Apple TV, or iPad as a home hub - Apple Support