OG Switches were amazing to hack. You literally just had to short two pins on one of the joycon sockets, then you could boot it into RCM/Recovery mode, and then you could inject a payload to run a layer between the OS and the hardware so you could tell the OS whatever you liked about the hardware. The ghetto method was to just use a paperclip, but you had to be careful because if you accidentally shorted a particular pair of adjacent pins you would brick the device. The better way was to buy a cheap little 3D printed jig, literally just a piece of plastic with a wire in it that slid into the joycon rail. You would then clone the system NAND onto an SDCard, running the console off the SDCard instead, leaving the original console completely clean and available to swap back to with a regular boot.
Then you had stores, freeware apps where you could just download games directly to the console. Nintendo started cracking down on those (although as usual you only seem to get their attention when you start asking for money) so most of them went away or into deep hiding.
On top of all that, when the Switch first came out it had a WebKit browser exploit that allowed complete hacking. It turned out this browser exploit was actually pretty widespread across other browsers on PC, and they were all subsequently patched.
Yes hah shove in an SD card, then open a “message” in a red envelope with a bomb on it, then a bunch of code executes and BAM you’re in!