Nintendo just announced today they are implementing Virtual Game Cards. As of now, you can share physical games with anyone you want, but you cannot do this digitally. Even if you have and are logged into two Switch consoles, the only way you can play the digital games you own, is a very complicated account sharing process. This all changes come April.
With Virtual Game cards, you wirelessly communicate with another Switch system, and it transfers from one system to another. Similar to sharing a physical game. You can do this with a Switch that you are logged into, and it's not a copy, it's a transfer. So if you have a Nintendo Switch, and a Switch Lite, this is for you.
The new feature also allows you to lend your games to anyone in your family group for up to two weeks. They will need their physical Switch and have to be a part of your family group to make this work, as this is not an online function, but rather an Ad-Hoc situation.
The discourse on this takes me back to a time when the Xbox One was announced, and didn't want used games to be shared. The reversed this idea upon release. Playstation successfully made fun of them because of this. There will be Steam users out there who will say they've been able to do this for a while. We get it. Just let people enjoy this. This is not a Nintendo thing. They're listening.