The purpose of the switchover to digital TV is pure greed on the government’s part.

There is a very limited amount of radio spectrum, the low end is sound and the top end is light waves (sound, radio and light waves are basically the same thing only different frequencies.)

The government rents out space on the radio spectrum to whoever has enough money to buy its use.

Digital signals take up less space then analog signals. This translates to a lot more space to rent out and collect money for its use by the government.

There is no commercial gain for television networks from the push to go digital.