that's why we should have kept copyright limited to human creators and not allowed them to be bought up by effectively immortal corporations who can pass, sell, or auction off those rights to other corporations. Just one more way the public is being robbed from art and creative works that should be freely and easily available to them to enjoy and build off of.
I don't see much of an issue with multiple individuals having equal share of a copyright though. We already pretty much have that now as it is. For a single recording of a song you're already dealing with a large number of rights that may not all be owned by the same people covering things like the composition, the performance/recording, synchronization, and distribution which could itself include separate licenses for different mediums (radio, physical media, streaming) or markets (domestic vs international), but somehow we manage to work it all out most of the time.
The important thing is that the problem of perpetual copyright goes away and people can start accessing and building on their own culture without fear of being sued for massive damages.
I think what we're really talking about here, if we wanted a copyright system that didn't allow corporations to own works, would be ending copyright assignment.
In that case, it's likely that part of your employment agreement would simply include a perpetual, exclusive, licensing agreement as well for all works performed on the job. It would be important that the company keep these licensing agreements on file, and would change the legal bias from "company presumed to own" to "company must demonstrate it owns," but that shouldn't really be that onerous. Companies already have to establish contractual basis for nearly everything they do anyways.
And it would put the cards on the table and it would probably make it easier (or at least more possible) to negotiate things like royalties on work that currently almost never gets it.
Also it'd make it a hell of a lot harder to exclude someone from the credits of a game because they quit 2 weeks before it went gold.
Exactly, creators would license their work to their employers and if not much much sooner, at least when the creators have died the copyright would expire and the company (along with everyone else) would be free to continue doing what they want with it.
Proving that no one owns the copyright to the satisfaction of any company or person who's even a little risk averse then becomes essentially an archeological or genealogical task that's rarely worth it.
This is why we get an endless stream of movies and books built on ideas from before 1920 and everything made since then that isn't a blockbuster of some sort languishes into obscurity. Eternal copyright is where ideas go to die.