It's not free content when you pay for the traffic.
You pay for the machine that turns radio signal into video/audio and you pay the opportunity cost of the radio bandwidth which is public property that is used for transmission of TV signal.
When was the last time you had a pay-per-use TV subscription?
And now even some mobile providers are blocking ads. I'm guessing that's because they're concerned that they won't recover investment in additional infrastructure. That is, providers who block ads and charge less will be more competitive than providers who allow ads and charge more.