I spent my covid years backing up all my dvds and blurays. Most, especially for TV, I dropped them. But for movies I kept as many as I could.
Some people will have gone for iso backups so they’re implicitly captured but I just did remuxes as separate files so they’re easier to use and play.
Raid/NAS, as many others have said, isn’t a backup.
However, you could have a single NAS and backup to AWS Glacier where storage costs for larger files is cheap going in and getting out in DR scenario is expensive, but maybe covered by your insurance depending on the DR event.