Yes, there is such a thing as a free lunch. But if you hack your Nintendo Switch to play pirated games for free, that comes with a cost: You can't play online.
Notable Nintendo hacker ScriesM took to Reddit recently to outline the anti-piracy measures Nintendo has put in place to sniff out consoles playing pirated games and banning them from the Nintendo network - permanently.
Nintendo stores an encrypted client certificate in the "TrustZone" core of each Switch, unique to that console. When you log in, Nintendo's servers identify your console by that certificate, which means if your Switch gets banned, it will stay banned.
As Ars Technica points out, 3DS hackers were able to fake a token to get a banned console back on the network, but that doesn't work with the Switch.
Games, both on physical cards and digital downloads, have their own encrypted certificates that identify them as legit. In the case of downloads, the encrypted ticket that's embedded in the game code also includes info about the console and user who purchased it.
Try to play a copy of a game that was purchased on another console and with another account, and boom, your Switch is banned. You won't even be able to play legit games online.
GIF: David Murphy
All these certificates are checked when your console goes online, so if you play pirated games completely offline, Nintendo shouldn't be able to detect it. However, that isn't 100 per cent certain. It's possible the console's firmware could detect pirated games you play offline and flag your console for banning when you go back online.
Ars Technica and Reddit have more detail, but the gist is: Nintendo has gotten very good at catching players who pirate Switch games. If you want to play any Nintendo Switch games online, either don't hack your Switch, or be incredibly careful.