There would be a sizeable portion of devices that do not support a second ssid or a second network. Also if you have more than one access point, the underlying

There would be a sizeable portion of devices that do not support a second ssid or a second network. Also if you have more than one access point, the underlying switched network would have to support 802.1q vlans to separate the two networks, a sci-fi in home network switching. Guest access approach adheres to best practices, but isn't as simple or as ubiquitous.