Should copyrights be good on a product forever , or untill its discontinued or no longer in production?

Answer 1

Yes.

Whether copyrights or trademarks, there is no reason to take the work of content creators from them at some point and simply declare that it is no longer theirs.

Answer 2

First of all, copyrights protect creative works -- art, songs, stories, software, literature, maps, etc. -- not products.

Protection for products -- inventions, processes -- is covered under patent law. Which has a much shorter life than the other forms of intellectual property, because it protects the process or invention even if someone else develops something similar through an independent design. Because it grants an effectively monopoly, patents have a very short duration (10~20 years).

Product identity -- logos, names, packaging -- those are protected by trademark, which is intended to prevent competition. Trademark protection can continue for as long as the product is in production, and I think that's a good idea because it encourages brand identity.

Copyright is designed to allow a person or company to invest time in a creative work, while preventing other people from copying or distributing that work. Copyright protection typically lasts for about a hundred years -- in the US its set at life of the author plus 70 years for people, and for works of corporate authorship to 120 years after creation or 95 years after publication. That way, the person and their children can benefit from exclusive sales and distribution rights, but after the longer period, it becomes public domain.

I think all three intellectual property formats got the numbers pretty close, based on the intent of the protection, and how much of the work is protected.