No. See Sony v. Connectix or Google v. Oracle if you want to know more, but basically, it is fair use to copy interface features such as APIs for the purpose of

No. See Sony v. Connectix or Google v. Oracle if you want to know more, but basically, it is fair use to copy interface features such as APIs for the purpose of interoperability or developer convenience. Nintendo's counterargument to those cases has to do with DMCA 1201, an extremely broadly drafted law that has to do with copy protection. A lot of console emulators have to implement decryption functions in the emulator because people are bringing in ROM images or ISO dumps that are encrypted. Console emulation has a habit of just grabbing whatever format the piracy scene is using and going from there, which is a bad idea and what enables Nintendo to, say, sue the shit out of Yuzu. At the same time, however, this isn't a critical flaw that makes all emulation illegal. Yuzu was also extremely sketchy in ways that let Nintendo connect the dots and say "this is infringement". There are plenty of emulators out there written by people who have good copyright hygiene that don't have this problem. e.g. WINE, Ruffle, PCem, DOSBox, etc. And none of this has to do with whether or not the emulator is being sold for money, is licensed as a Free Software project, developed by a community, etc.