There's a problem with this: What if the work is 'available', but only for an outrageous fee? It wouldn't even be that hard to make a legal argument that a $100,000 fee for a single copy is 'justified', since some people have been willing to pay that much for copies of mass-market media (on the secondary market) in the past. Or distribute them via a group-buy system, saying it's only available via commercially pressed BDs, so it's not worth spinning up the presses again unless 2000 people commit to buying a copy in a given timeframe (and then still charging something like $200 per copy with some nonsense about it being a 'premium' edition), delivery then takes 50 weeks. Niche commercial software (industrial control, telecoms, that sort of thing) can costs millions for a copy, so maybe you could 'genuinely' believe that your game's server code costs a million dollars per unit, even for non-commercial use.
Now, all these arguments are pretty poor, and wouldn't stand much chance of winning in court, but the fact that there's a bunch of arguments that could be made makes stalling a lawsuit out until the defendants run out of money a much more dangerous possibility.
I think this law world get us a substantial amount of the way. There are so many seemingly abandoned works, sometimes even ownership rights aren't clear. Many of those would likely just end in the public domain.
I think a bigger issue is that video games and movies frequently have licensed other media like music in it. The musician might be very actively selling and licensing their music but now I can just get this abandoned video game and extract the song?
Now, all these arguments are pretty poor, and wouldn't stand much chance of winning in court, but the fact that there's a bunch of arguments that could be made makes stalling a lawsuit out until the defendants run out of money a much more dangerous possibility.