IP rights were always intended to expire. If you look up original copyright and patent laws you will see the words "for limited Times" very quite prominently. Originally the idea was you create something, you control it for awhile, then it becomes a cultural asset that belongs to everyone. The law was changed to keep extending the period these pieces of our culture "belong to them" instead of belonging to all of us.

Reading your question I worry how many people assume their cultural icons should rightfully be controlled by corporations instead of belonging to everyone who grew up with them.

Referencing or reinterpreting old works used to be a stable in culture. But even with fair use laws (and not every contry has them) it is a legal minefield to use anything that isn't public domain. So while copy right laws are intended to foster culture work production, the extreme long terms (105 years) actually harm it.

ps disney itself build their animation film success partially on public domain fairy tales while simultainosly working on getting copyright laws to a point where no new public domain fairytales will be created ever again.

That definitely happens with trademarks. In fact, they're designed that way. You get to keep it as long as you're using it.

Trademarks can also become so widespread that they become generic, and then the company is in danger of losing it. Kleenex, for example. This is something of a "victim of your own success" problem.

I wish there was a better mechanism for this on copyright and patents. There's no good reason that a 30 year old video game that isn't being actively developed should still be in copyright. Patent trolls who figure they can make more money by suing people than by licensing out the tech should be shut down.

As a musician, IP law is anathema to the development and expression of culture. As musicians we are raised on music in the public domain (classical music, folk songs), we cover bands that are inspirational to us, we reference famous melodies or ideas in our work. It isn't all just cold-hearted capitalist thievery. Quotation used to be a normal aspect of music (even the greats like Beethoven did it) but it you get organizations like the Marvin Gaye estate who frivolously sue any artist who even considers referencing his music. What does that leave culture? Is it a good likelihood that Gaye's music will have as much staying power over the centuries if his estate fights bitterly to quash his music from being referenced and disseminated?

From Wikipedia:

[American legal scholar] Pamela Samuelson has identified eight "values" that can arise from information and works in the public domain

Possible values include:

1. Building blocks for the creation of new knowledge, examples include data, facts, ideas, theories, and scientific principle.
2. Access to cultural heritage through information resources such as ancient Greek texts and Mozart's symphonies.
3. Promoting education, through the spread of information, ideas, and scientific principles.
4. Enabling follow-on innovation, through for example expired patents and copyright.
5. Enabling low cost access to information without the need to locate the owner or negotiate rights clearance and pay royalties, through for example expired copyrighted works or patents, and non-original data compilation.
6. Promoting public health and safety, through information and scientific principles.
7. Promoting the democratic process and values, through news, laws, regulation, and judicial opinion.
8. Enabling competitive imitation, through for example expired patents and copyright, or publicly disclosed technologies that do not qualify for patent protection.