This isn't really my scene so I don't know the details, but I remember reading that the first 10+ million Switches produced have an unpatchable bootloader exploit. I'm sure you're correct that almost nobody actually has a hacked console, but my understanding is that they're readily available for people who want one.
This doesn't surprise me much, but does Nintendo state this explicitly anywhere public?
If Nintendo chose to sign an application developed using a 3rd party toolchain, there's no technical reason why it couldn't run on retail consoles.
Block Nintendo servers, disable auto updates, use separate sysMMC and emuMMC with no unauthorized games or DLC run on the sysMMC. If you follow the main guide everyone uses now, it's pretty safe. But updating becomes a more difficult and manual process. Have to grab a zip of the new firmware from the 'net on your PC and copy it to the SD card to be installed via a homebrew method. Installing games, game updates, and DLC is similarly manual. It's not like the PS3, Vita, and 3DS(?) where you can pull it all off of official servers easily.
Oh yeah, and we're stuck with a "tethered jailbreak", that's perhaps the worst part. Any time you turn off the hacked Switch it needs to be sent a payload from your PC or phone to boot up again then.
Whether it's all worth it depends on your needs I suppose. You could get a bunch of tournament setups going with Smash (or another fighting game) + all DLC for your LAN party and save a bit of money. You can try out new singleplayer games before buying them physically. You can mod games and run emulators. Honestly the Switch scene seems largely less cool than what we had with the 3DS or Wii (Wii U was a little disappointing as well). I barely touch my Switch(es) since getting a Steam Deck.
Modchipping makes things permanent, although the soldering isn't for the faint of heart.