Connected Devices - What Kind of Infrastructure Do We Need?

IoT devices are not just an embedded product, it's a system of systems, right? So I have my connected device, I've got a couple phone applications that talk to that device and I'm going to have a server so I can remotely send updates to devices. At a minimum, with a connected device, you're going to have those kinds of things. How common is it for devices to directly connect, say, over cellular or possibly Wi-Fi, as opposed to communicating over Bluetooth with a mobile app on someone's phone)? These are week for consumer devices.