The correct term is: bootleg, in this case. As in for example: the real Switch 2 is expensive, so bootleg imitations (knock offs) exist sold for cheap. You can encounter that in a literal market where they are selling fake iPhones, watches, handbags & etc.
You could 3D print a game console but it’ll be obvious as it won’t work without internal components (GPU / CPU), you need to obtain a schematic of its design in order to really create a copy. An iPhone is made from aluminum for example.
anyone with the skill set to build that and access to the supply chain and fabs required to build it isn’t going to risk getting sued for that.
but you can buy retro style devices that can emulate most consoles older than 20 years, they’re pretty common. some even go as far as literal cartridge compatibility.