Well, first while raid is great, it's not a replacement for backups. Raid is mostly useful if uptime is imperative, but does not protect against user errors, software errors, fs corruption, ransomware or a power surge killing the entire array.
Since uptime isn't an issue on my home nas, instead of parity I simply have cold backups which (supposedly) I plug in from time to time to scrub the filesystems.
If a online drive dies I can simply restore it from backup and accept the downtime. For my anime I have simply one single backup, but or my most important files I have 2 backups just in case one fails. (Unfornately both onsite)
On the other hand, for a client of mine's server where uptime is imperative, in addiction to raid I have 2 automatic daily backups (which ideally one should be offsite but isn't, at least they are in different floors of the same building).