Your games are tied to your account. So if you pick up another switch your can just relink your account and get all your games again
You might even be able to plop in your SD card after linking and not have to re-download, though I haven't tried that myself.
Your save data is a different story. Nintendo locks that to the console, no copying to SD allowed. As egg mentioned, you can use cloud backup to preserve your save data if you have NSO, but there are a number of games where this isn't available.
https://en-americas-support.nintendo.com/app/answe...