Because you didn't pay for the content.
Assuming it's analogous to the Dutch law, the tax compensates lost income from you being able to store publicly broadcast copyrighted materials, such as music on the radio or movies shown on TV. That's why it is taxed on storage devices and varies per device type.
You haven't gotten a license on every piece of music, software, and movie in existence. That would be great lol, I'd sign up for that tax. Essentially, that's what Netflix was for movies until Disney etc. decided they wanted not to participate and now we wonder why piracy hasn't died
This money, instead, goes to copyright holders. The amount is set to cover minor household use, like copying from a friend or a broadcast. It's not to absolve you from copyright law as an individual altogether and make you never have to pay for a movie in your life
If that's what you want, parliament is the assembly you will want to talk to, but I'm afraid that they're bound by international treaties and, even if not, the height of the tax that absolves you of all copyright ever would be more than you're willing to pay
I'm just explaining how the law works in my understanding (and, interestingly, not getting any upvotes for it. Usually accurate comments are upvoted but then, usually, people don't disagree with the law. People don't like this messenger!), not saying I agree with it
In some sense, this is a rent extracted by large IP holders, and consumers are getting the short end of the deal just as much as the artists. But arguably it's also a bureaucracy-minimizing and thus cost-minimizing approach at country scale: the alternative to a flat fee paid by some amount of commercial entities (and passed onto buyers through prices of hardware), would likely be dealing with individual-level enforcement, lawsuits targeting individuals and/or some other high-maintenance mess, all ultimately paid for by the taxpayer anyway.
I'm in France and you do actually pay for it through this tax since all the income goes to a private company like the RIAA.
The "upside" to this is that the surrounding laws allow us to make private copies for our own private use.
All this to say it was normalized in the US. I don't think it is stigmatized even today. More like we had about a decade of streaming services actually providing good value. But now the product managers and UX designers have their hooks so deep in it that it's becoming unusable.
Those fees are here just to compensate the fact that you COULD copy your legally owned content and that it COULD represent a loss of opportunity for the rights holders mafia (because that’s what they are). Oh, and that compensation is calculated by an organization representative of … the rights holders.
Why the hell would I pay a fee for something I might do? I mean, what? How is that a thing?
My car can go 140mph. Does that mean I should be in jail for speeding?
And now there is an intense lobbying not to change things.
Something I've never done and will probably never do. I also don't know of anyone who ever has. The fee should completely go away in the age of streaming services, but I doubt rights holders agree.