It's not a tax, it's a licence fee. Tobacco duty is that the level of this is set by the government and the government can do what they want with it: it's supposed to be spent on the increased medical care that smokers need but basically the government can and does do what they want with it.
The licence fee, while negotiated with parliament, goes to the BBC and this is the best way to provide an element of independence and objectivity for the media, above and away stupid attempts to be "fair and balanced" by treating all idiots equally. With financial independence the BBC acts as an anchor for the rest of the broadcast media to measure itself against and compete with. The BBC isn't perfect so commercial operators can compete with it over both quality and ratings.
Arguments about technology are wilfully designed to miss the point: the mixed market of British broadcast media: giving people what they want isn't the same as giving them a choice.