Yes. I 100% unironically believe that anyone should be able to use anyone else's work royalty/copyright free after 10-20 years instead of 170 in the UK. Could you please justify why 170 years is in any way a reasonable amount of time?
May I ask why you want to use someone's work instead of creating your own?
I mean, it's fun. Ever listened to the KLF, and things from the era before sampling was heavily sat on, such as the album 1987 (What the Fuck Is Going On?) - ? I don't claim it's very good, but it was definitely fun. And the motivation for using existing works, instead of creating your own, is similar to the motivation for using existing words, instead of creating your own. They're reference points, people recognize them, you can communicate with them instead of having to extract patience from the audience like they have to learn a new language for each work. And of course in practice the rules are fuzzy, so everybody sails close to the wind by imitating others and in this way we share a culture. Stealing their work is just sharing the culture more closely.
> is similar to the motivation for using existing words
I don't think it's like that. If we take music, for example, the existing word would be a note or a scale or a musical instrument or a style, but a melody would be an existing sentence. As for sampling, there is creative usage of samples, like Prodigy for example where it is difficult to even recognize the source.
Also today there is some leeway in copyright enforcement. For example, I often see non-commercial amateur covers of commercial songs and the videos don't get taken down.
I put it to you that same difference. These matters of degree are what copyright lawyers haggle over. It implies to me that the whole edifice is forced into being, for its desirable (?) effects, and has no concrete foundation. Nothing pure and elegant and necessary about copyright.
Well, you asked why, anyway, and there's why: it's a natural thing to do.
The copyright last 70 years after the death of the author, so 170 years would be rare (indeed 190 years would be possible). This was an implementation of a 1993 EU directive:
https://en.wikipedia.org/wiki/Copyright_Duration_Directive
That itself was based on the 1886 Berne Convention. "The original goal of the Berne Convention was to protect works for two generations after the death of the author". 50 years, originally. But why? Apparently Victor Hugo (he of Les Miserables) is to blame. But why was he bothered?
Edit: it seems the extension beyond the death of the author was not what Hugo wanted. "any work of art has two authors: the people who confusingly feel something, a creator who translates these feelings, and the people again who consecrate his vision of that feeling. When one of the authors dies, the rights should totally be granted back to the other, the people." So I'm still trying to figure out who came up with it, and why.