There are some significant edge cases that can plainly make that unfair.

Let's say Kurt Cobain dies at 27 (or even younger) without an heir other than a very young daughter. ~95% of his earning capacity might be in the next 15 years, rather than the prior 5 years. The daughter might be cast into relying on charity while everybody else gets to freely commercially exploit his music after his death.

('the US social safety net needs reformed'; pre-empting those responses, because one is extraordinarily difficult to reform, the other isn't nearly so; that'd just be an excuse to hide behind)

Ritchie Valens comes from a poor family, creates a gigantic hit, dies at 17. His family deserves nothing specifically, while everybody else gets to freely commercially exploit his young talent forever.

A life of the author clause is inherently cruel. 20 years fixed, approaches that in a far more reasonable and fair manner. Families / heirs matter too. They often suffer, or otherwise carry a share of weight for the artist, so the artist can create, tour, publish, publicize, etc. Pretending otherwise is pure fantasy, it's life in an idealized vacuum.

I agree that's a potential loss with a 20 year or life term, but I still argue this is a net gain for the world.

Edit: I might be flexible on the life part. But not the 20.

Personally I would not involve the authors life at all in the term (then again I think the ideal term length is zero) but I also don't see an artist kids not being able to profit from their dead parents works anymore unfair than a cobblers kids not being able to profit from their parents works after death. Life isn't fair. If someone needs welfare than I am in support of making sure it is available - but please let's not use it as an excuse for unrelated laws.

Would you like this for all assets, basically banning inheritance. Govt will seize all property, savings, stocks etc on a person's death.

False premise. Intellectual property is not equivalent to those assets.

No.