This is an example of a "natural monopoly", where a limited community resource is owned as property by a corporation. In this case it's the easements and permission needed to run the phone lines, and the RF spectrum for cell-phone service.
If you treat the resource as property, you get the situation we have now: high fees for access and discouraged use. Phone service has high monthly fees (access) as well as data caps, fixed monthly "minutes", and roaming charges (discouraged use). Similarly for internet: high monthly fees (access), data caps, throttling, kicking off high-usage users, and so on (discouraged use).
As an alternative, take the revenues from the carriers and divide by the total minutes of service. I don't know what that figure actually is, but for purposes of discussion let's say it's 5 cents a minute. A similar calculation can be done per gigabyte of internet data.
Suppose the government mandated that carriers could only charge that amount or less, with no other restrictions. Any phone could be used with any carrier, and you choose a carrier at call time by scanning the available carriers like we scan wireless access points. (You wouldn't explicitly scan for each call. Most likely you choose one carrier as default, like we now do with wireless access points.)
Now instead of making money by getting people to sign up and not use the service, carriers make money the more people use the service. They have to encourage more people to use it, and for longer periods. They have an interest in putting unused capacity to work, and promoting innovative new uses. If a channel is overallocated, they have an interest in building out more capacity.
The reasoning can be applied to cable TV, internet, and phone service. If the cable company can only charge 15 cents per hour of viewing/downloading (whatever the fee structure works out as), then they will encourage more usage rather than throttling.
If this change is made, the existing players will make the same profit as now: initially the profits are the same, and no workers need be laid off. Their bottom line doesn't change, only their focus of service.
It's game theory: change the rules so that the outcome is more desirable.