1. •It only supports voice grade audio quality. Its two copper wires are strained to carry data, which must first be converted to an analog sound signal (that's what a modem does). Internet data services and video conferencing demand far faster data throughput than the existing phone system was designed to support.
   
   
2. •Calls are a circuit switched model. Making three-way or conference calls are not innately supported by the old phone system; both require special equipment or operator intervention that makes them expensive and complicated to set up. Further, the old switchboard model does not support modern data packet features for end users, like caller authentication, call encryption, or advertising presence information, such as: free, busy, or unavailable.
   
   
3. •It is based on a pay per call billing system. The old phone network was built upon a business model designed to bill users proportional to the number and length of calls they placed. That works fine in a circuit switched system, but for a packet switched data system, where users demand always-on connectivity and may rapidly connect to hundreds of hosts or open long and sustained data connections, it's more desirable to pay an upfront fixed fee. In the US, Internet service is almost always paid for with a set or unlimited usage fee.

1. •It's a simple system. The phone system's simplicity means that it is much easier to deliver basic service to remote locations, or restore service after a disaster, and much easier to troubleshoot and maintain in flawless, nonstop operation, particularly when compared to managing a high speed data network. There's simply less to go wrong.
   
   
2. •It's a robust system. The old phone system is fairly bulletproof because it was designed as a high-availability system. Phones can be powered directly from the network, and often remain in operation even during a blackout because the phone companies run their own emergency power. Emergency services such as 911 depend on that type of availability.
   
   
3. •It's a utilitarian monopoly. No free market enterprise would pay to string phone wires from a cabin in Montana or an remote island off Alaska. Governments establish monopolies for utilities, granting them freedom from competition in exchange for the responsibility to serve the public in unprofitable ways. They also collect taxes and fees on communications to make the system self sustaining, so that the monopoly can provide all users with affordable service.