2. If you sell a widget, that item gets irreversibly transferred to the buyer. If you sell your time (ie. what you're doing as an employee) the same thing happens with your time. If you "sell" a movie, that doesn't happen. Well, technically that happens all the time between companies, but doesn't apply to the typical consumer transaction. "perpetual IP based income" is a way to make products that are infinitely copyable have a viable business model. Otherwise if you want to watch a movie, you'll have to pay for the whole thing.
For the creators, copyright is effectively perpetual. It expires eventually, but rarely until after you're dead. "As a general rule, for works created after January 1, 1978, copyright protection lasts for the life of the author plus an additional 70 years. For an anonymous work, a pseudonymous work, or a work made for hire, the copyright endures for a term of 95 years from the year of its first publication or a term of 120 years from the year of its creation, whichever expires first." https://www.copyright.gov/help/faq/faq-duration.html