I could certainly imagine an alternate future that if CC got enough donations to back a big enough budget they could help pay for lawyers to full time help creators claw back IPs from major corporations with the hopes to CC or CC0 license the rights that they win back. I also imagine that would cost a lot of money and that hypothetical arm of CC would need a huge budget to win the legal fights it would want to take on.
Google for Library Genesis, Sci-Hub, Z-Library, ... ;-)
But on the other hand if that was done on a large scale it might set an expectation that old things are bought out, or even that anyone ought to be paid to release anything free at all, and that sounds very bad.
You'd be better off lobbying to weaken copyright protections. There are several charities interested in doing so, but they all have different kinds of baggage: donating to the FSF means Stallman's Way or the Highway, donating to the EFF means supporting Protect The Stack[0]. RPG[1] is run by Louis Rossmann who is fairly chill[2], but they're also the weakest in terms of anticopyright. Nobody wants to purely abolish or reform copyright; they want to do so as a means to achieve some other ends.
Putting that aside, there's also the problem that proposals to reform copyright go absolutely nowhere. Copyright maximalism is pretty uniformly supported by almost the entire US political class[3] and even very mild reforms like right-to-repair face fairly extreme bipartisan opposition. Not even the fascist-lite (DeSantis/Trump) wing of the Republican Party is willing to kick Disney in the copyright balls.
Illegally speaking, the Internet Archive is perfectly willing to publicly archive works they don't own, and they are saints for doing so. But they are also having their balls sued off.
[0] To paraphrase a lot, it means "ISPs should not have abuse desks".
[1] Repair Preservation Group
[2] He does have a right-libertarian bent and an axe to grind against New York's government, though that can be explained by them trying to kill his business
[3] Corporate leadership inclusive. Most corporations should be considered to be a kind of shadow government, not just as private entities.