Are you sure you could get 32TB down from cloud in only 4 days?
Backups are a good thing and we recommend everyone have another copy of any important and irreplaceable data whether they have parity or not. Unraid parity or indeed any traditional RAID isn't and never has been a substitute for backups.
Rebuilding a disk from 8TB parity should take only a day +/- a few hours but that is perhaps not a fair comparison since you were claiming you could download ALL data in 4 days.
But as mentioned, the purpose of parity isn't to serve as a backup anyway. Redundancy allows you to keep going even when a disk is missing and while the disk is rebuilding. There is some write performance penalty with parity but there are 2 modes for that. One mode is slower but allows all disks except the disk to be written and parity to be spun down, and the other mode is somewhat faster but requires all disks to spin.
And of course, if you were actually rebuilding a disk, while you would still be able to access all your files (including those from the missing disk) and continue to use the array, performance would also be impacted during the rebuild.