But building an emulator, that allows you to potentially use copyrighted software on a different platform without the explicit permission of the platform holder, is illegal, and its a fight you will always lose in court if the owner of said copyrighted material decides to do something about it.
Source? Because the Bleem case proves you wrong.
If any of this shit was perfectly legal, and there is no copyright law about having an emulator that allows you to play the games of another platform on a different platform "as long as you own the game", then nothing at all would stop Sony or MS from making a switch emulator on their consoles. Or MS from making a PS emulator on their own consoles. Or isn't that the exact same thing?
They can, but they wont. Because:
1. These companies can barely create emulators for their own past systems. For years now they are struggling to make a single emulator that is as good as the homebrew ones.
2. There's no point in making an emulator for a competing system because they can't sell a game they don't have the right with it. Only when they have the right, like the recent Goldeneye remaster which was released on XBOX and it's basically a N64 game emulated.
3. There's no point in making an emulator for a competing system because why would they want to compete against their own software?
4. Companies would never release a standalone emulator, not even for their own systems. They only release
games where the emulator is in the background. Why would they release an emulator, they don't have anything to gain.
And do you think this is the first time something like yuzu is being taken to court or issued cease and desist orders?
No it's not, companies have tried it with other emulators in the past and they lost.
Again, making an open-source emulator is legal, playing ill-gotten copyrighted software on said emulator, is illegal.
Correct. Playing ill-gotten copyrighted software on said emulator, on a computer, using a screen is illegal. But in that chain not the screen, or the computer, or the emulator are at fault. The fault is
playing ill-gotten copyrighted software no matter where. Could be an emulator or a hacked device or a virtual machine or whatever. You can play cracked PC games on Windows without having to use STEAM or any other platform, should we ban Windows as well?