Copyright has a purpose. I don't mean a purpose in the Disney Hegemony sense but a real, actual purpose.
Dropping copyright cases is great if you hate proprietary code. That's fine. Open source is also powered by copyright. If we start dumping copyright cases we don't get the "well bob we may as well open source it!" We get large companies like Google just completely ignoring copyright and using open source code without attribution. What you've described (causing enough a problem in the courts) is the exact purpose of GPL. If we start dropping copyright cases altogether the open source movement may as well be dead in the water.
Now I hope that Copilot sticks around for this exact reason: cause endless inane lawsuits claiming that actual original code was stolen and laundered through Copilot or reverse engineers going cowboy. Make it enough of a problem clogging the courts that they start dropping copyright cases.