Many devices nowadays no longer have Ethernet ports — Macbooks (both Air and Pro), Ultrabooks, hybrid laptop/tablet devices like the Asus Transformer or the Microsoft Surface, traditional tablets like the iPad or the Nexus 7, and phones. None of these devices have Ethernet ports.
Often the solution is adapters, which are clunky, another item to buy, keep track of, carry and lose, not to mention that they cost money. Why not instead just use USB ? I should be able to connect two devices using a USB cable and just have it show up as an Ethernet connection on both ends.
Or plug my laptop into a USB port on a router (most routers already have USB ports). In an office or other setting, the router itself can connect to the LAN using an Ethernet cable. That’s fine, and I’m not proposing using USB all the way through; only on the final hop to my laptop.
USB cables are also thinner and less bulky than Ethernet cables.
And USB 3 is faster than Gigabit Ethernet — 5 Gbps vs 1. USB 3.1 doubles the speed to 10 Gbps.
It’s time to switch to a connector that’s supported almost everywhere, is faster, and uses less bulky cables.
 USB was a master-slave rather than a peer-to-peer architecture. Any given port had to either work as a master or as a slave, which means that you couldn’t connect two Macbooks together. But USB OTG, which stands for On The Go, fixes that, letting you connect a device with a USB OTG port to any USB port.