How do you believe copyright is keeping the quality down in particular? As I see it, the reason is marketability and trying to conform to standards. Making a new Marvel Movie is sure to have a payoff. Making Parasite MIGHT have a higher payoff, but the risk is way higher.
Removing copyright might help to get various more spin-offs and reiterations on previous work, which does increase the scope, but taking the ability for makers to profit from their work in a traditional sense, will bring us closer (back) to a time when commissioned artwork was the main art you saw
Letting "makers" (studios) profit from "their" (stolen by unbalanced contracts) work for unreasonable amounts of time has clearly proven to be a failure while crowd-comissioned spaces (patreon etc) are thriving financially AND artistically.
Removing copyright might help to get various more spin-offs and reiterations on previous work, which does increase the scope, but taking the ability for makers to profit from their work in a traditional sense, will bring us closer (back) to a time when commissioned artwork was the main art you saw