Can't remember any other tax-like charges where one has to pay for something artificial that they could be completely unrelated to, yet don't have any control over.
Most people would rather discuss it in terms of "funding an independent source of media" and "building road infrastructure to move goods and services".
For roads, maybe somewhere it's the same, but there are also funding ways that work differently. If you use the road (have a vehicle) you (probably, depends on where you are) pay the tax, either directly or included with the fuel price. If you don't drive a vehicle but use the roads indirectly (because the services you use, use that roads) you pay indirectly - trough your funding of those services and their respective use of vehicles. E.g. you buy stuff in a grocery store, the store pays to a transportation company, the transportation company pays taxes for their trucks - everyone's paying for what they actually use. So, it still feels fundamentally different from the broadcast taxes to me.
In the US, various forms of taxation at the federal, state and local level go in to providing funds for public schools. Everyone pays for schools even if they have no children. The only significant exception is that in some places, parents can receive vouchers to pay for private schools. Either way, the goal is that everyone receives a basic education to make a better society.
Everywhere in the US I've had a library card, it was similar. Libraries are funded by general taxes and their basic services are provided without charge to users who live in their tax area (county, most places).
Whether publicly-funded radio stations are a valuable public good in this way is reasonable to debate, but that's the model.
But of course it's not only financially. The German Rundfunkrat is basically designed to be the very essence of what other cultures might dispraise as corporatism. - Despite it's justification as some cross section of society.
I'm not necessarily against the idea but the institutional design of German state media is arguably very bad.
>> It's not a tax by design though it may feel like one.
If I'm forced to pay money to the government for a public "good," it's either a tax or extortion -- there's no other way to define it.
It doesn't matter if the cause is "worthy" or not -- it's a tax. Why not let the people that consume the product pay for the product? Imagine if the government forced everyone to buy a Spotify subscription. It's the same exact thing.
Now, there's a ton of things that are wrong with our nominally independent radio/tv stations, but if I look around and see how things go in other states on this little planet (hello fox news), I don't have any idea that works better in principle. I'll take the german system over any alternative so far offered (though the BBC is a close contender)