I don't want to get into a political argument, but just for the record, the BBC is not a government news network. It is funded via tax, but it is independent.
aside from the fact that for a variety of reasons, the BBC is not truly independent, if it's possible to build such an independent media company "funded via tax" then why isn't it possible to do the same for a social media company?
There's a continuum of infrastructure from electricity, telephone, ISP, email, social media and beyond. If we can run national utilities at the start of that scale, not necessarily nationalized, but nationally regulated, I don't see why we can't run them at the other end of the scale.
I think the real problem is that current models of social media are dreadful, although I don't know of anything better.
I was replying to a narrow point that the BBC is a state broadcaster. If these things go uncorrected, misinformation can spread, especially given the global perspective.
I've not read the proposal. But some things, like telephone common carriers, ISPs should be regulated to the gills. Do I trust British Telecom Open Reach now they've been privatised? No, not really, but that's the way natural monopolies work. I don't trust them any more or less than I would have done pre privatisation.