It's an interesting solution, but doesn't solve a lot of the nuanced problems of home automation. For example, a tablet only has Wifi and Bluetooth, so it can't control devices that use Zigbee, Z-Wave, and Infrared, like we can.
Zigbee and Z-Wave aren't well known yet, but they're used by August, GE, Bosch, Honeywell, Logitech, Kwikset, Iris/Arcus, D-Link, ceiling fans, window treatments, etc. They're important for home automation.
You could use Alexa and buy a hub for the other protocols, but then you're telling Alexa to use the Z-Wave hub to tell a device to perform a task. And then you have to remember which devices are controlled by what hub. It's a lot to remember and keep straight.
Or, you could get AtmosControl and be done. Think of it like a universal remote control for all of your smart home devices, even if they're from a variety of manufacturers and use different protocols.