Unfortunately, most of us don't live in a perfect world and have to connect devices to our networks such as phones, IP cameras, printers, badge readers, access points, etc so for that reason, profiling comes in.
In a perfect world, you could authenticate your hosts onto the network with either dot1x or going through a guest portal but the reality is that not every device connected to your network will have the ability to navigate the guest flow or utilize dot1x.
