The physical star topology also ensures that a problem on one device will not affect other users on the network. LED indicators on the hub alert you to these faults, helping you immediately identify and resolve problems on one link while the rest of the system continues running. Finally, hubs operate over a building's structured cabling system - in most cases, the unshielded twisted pair telephone wire already installed in your office. That means every location with a phone is pre-wired with a network connection, letting you avoid the difficult and disruptive task of running your own cable. I already use coaxial cable.
Coaxial cable is fine for networking.
First, a twisted pair-wired network is much more reliable because of the physical star topology. Problems are a lot more common on coaxial networks, and they're much more difficult to troubleshoot. That can mean the difference between a whole network being inoperable for several hours versus one person being down for a few short minutes. Second, unshielded twisted pair is plentiful and readily available. Unshielded twisted pair cabling typically consists of four pairs of wires wrapped in a common sheath.