In just over 18 months time the BBC will be 100 years old: how long will it last after that?
My own view has already been picked up on in other quarters: if the country ever gets FTTP* to every household I can see a big drive to turn off all the TV transmitters on some financial/'green' codswallop and drive everyone to TV over IP - this in turn will push the BBC into being funded on a subscription model. I can imagine radio remaining free and "over the air" as it has a role to play during difficult times such as flooding or very poor weather - plus of course, reception in motor vehicles.
This of course assumes that by then, Johnson and his merry band, aided by Dacre at OFCOM, haven't just shut it down.
*Fibre To The Premises.