This 3-2-1 backup strategy is missing a dimension: time. Data is rarely unchanging. The 3-2-1 strategy is inadequate for changing data, because if you delete the wrong database table and didn't realize it, the 3-2-1 backups are going to be missing the table too.
You need to add the time dimension and have a monthly snapshot for data that is older than a year, weekly snapshot for data within last 1 year, and daily snapshot for the last 90 days.
You need to add the time dimension and have a monthly snapshot for data that is older than a year, weekly snapshot for data within last 1 year, and daily snapshot for the last 90 days.