Found a neat quote from the judges in the Sony v Connectix case:

“For this reason, some economic loss by Sony as a result of this competition does not compel a finding of no fair use. Sony understandably seeks control over the market for devices that play games Sony produces or licenses. The copyright law, however, does not confer such a monopoly.”

Now, it’s worth noting that Connectix actually produced their own BIOS, so this is not quite the same as the common emulators of today.

But still: The idea that copyright does not confer a monopoly on hardware to play your games would be a very spicy take from a court in 2024.