Why is WiFi such a popular way to implement a home network?
WiFi is a simple solution for creating a home network.  It eliminates the need to physically connect each client device to the WiFi access point with a cable.  Some devices such as smartphones and tablets often lack an Ethernet port which leaves WiFi or another wireless protocol as the only options for network connectivity.  The convenience does come at a cost since air acts as a shared medium which limits both the number of clients a WiFi network can support as well as the bandwidth available to those clients.