Nintendo Gamekeys check all of these boxes save one. Namely 1,2,3,5 and 6.

1. Keep it forever without the risk of remote deletion.

2. Use it while offline, unless internet connectivity is strictly required for the experience.

3. Move it between my devices.

5. Resell it.

6. Pass it on to my children.

No backup and archive is the exception. I can live with that. We'll see if Sony and Microsoft follow Nintendo or not.