Are we assuming that the incremental backups are each on separate drives? And the main backup body is on a different drive again?
I am pretty careful. I'm retired and there isn't much at stake on my computer that is worth a lot of money. But in the past, that was different. I recall a fairly big job that I did as a consultant, and soon realized that my files for this job were worth much more than the computer. I carefully kept serialized versions of all the important documents and maintained them on several different disks. All important files were backed up daily.
Times have changed and that is not necessary any more.
One incremental backup tends to take all the files from all your disks and put them together in one destination. That can be a disk or online.
Main thing people don't want to lose are their photos. They're important