Share Switch Online friend codes on mobile update, version 2.2.0
・ You can now send friend requests using your friend code. (Accepting a friend request requires a Nintendo Switch console.)
・ You are now able to copy your friend code as a URL and/or save it as a QR code, which others can then use to send you friend requests.
・ Other minor changes have also been implemented.
・ System requirements have been updated to iOS 14.0 or higher.
As you can see, the implications are pretty great overall. If you're randomly meeting someone for the first time, sharing a friend code is as simple as getting out your mobile device and making the exchange that way: even in the form of making a QR code for someone else to use on the spot.
Remember of course that there has to be provisos because it's the friend code system. To accept it, you need to use the Switch console itself when you actually get home. Also, you need specific versions of your chosen OS (iOS 14 for Apple, Android 2.2+) to actually use this feature.