How long do you keep your backups? A backup taken last night is great if your computer gets hit by a bus, but isn't so great if you just discovered that photos you took ten years ago were corrupted sometime between then and now.

The solution to that is rolling backups with different tiers.

1 backup updated daily

every week you update the weekly backup

every month you update the monthly backup

every year you update the yearly backup

and so on or with whatever precise timings make sense for you

Keep at least the last two snapshots for each.

Also, do use error correction codes so you can recover partially damaged backups.