I'll do ya one further: Copyright should have the same lifespan as a patent. 20 years max. No extensions, no exceptions. I'd even cosider less time than that.

If you retained the unilateral rights to copy your idea for 20 fucking years and you haven't made your healthy profit on it already in that time, tough. Your work will forcefully enter the public domain so people who were likely actually still alive when it was culturally relevant get a shake with it.

There is no reason why something created during my childhood ought to still be languishing locked up in trust of some dead man's corporation by the time I've withered away of old age and my grandkids have done the same. The severe generational lag of culture and accessible technology created by copyright in its current form is absurd.

If you want to chase your golden goose forever, keep making new iterations of it that have their own copyrights that fairly compete against everyone else's in the marketplace of ideas. Get off your laurels. Get on your toes. Keep making new, inspired things. Earn your goddamn right to continue being seen as the rightful creator to follow up what you've previously made in the past.