I get the sentiment but writing the Great American Novel is no easy proposition. Everyone who is saying 20 years are plenty should first make sure their wealth doesn't come from a salary. Creators are taking the risk so deserve the reward. I'm fine with ending with the creators death. This does push the creator to keep creating to maximize earnings for their estate prior to death. Creation is hard and it shouldn't be like art where paintings are only valuable posthumously.
the problem is that very rarely creators own the copyright, most of the time it's transferred to corporations. in principle I agree with you, but corporations should have restrictive limits (i.e. 20 years after first copyright transfer from a natural person) - and just to be sure, make it so that royalty contracts are null and void if they cover a duration longer than 5 years, so that corporation cannot workaround the issue buying new property for pennies using forever exlusive royalties and preventing renegotiation once the property becomes famous (i.e. avoid the current musicians/labels contracts where unknowns get scouted early and chained forever)
