Most definitions of the 3-2-1 rule count the original data as one of the 3 copies [1][2][3] and don't go as far as to specify that you should be diversified against literal medium type. (Most recommend an external drive or NAS for your second local copy)

The "my house was hit by lightning" case is covered pretty well by your 1 offsite backup.

1. https://www.acronis.com/en-us/articles/backup-rule/ 2. https://www.carbonite.com/blog/article/2016/01/what-is-3-2-1... 3. https://www.backblaze.com/blog/the-3-2-1-backup-strategy/