As I said earlier, the roots of verification date back to days when writing media were less reliable. If you think about it, now we do terabytes of writing to modern hard drives, and data loss is rare.
Far be it for me to advise that verification is not needed, but I would like to challenge users here when was the last time verification failed on modern hard drives. Even when I did do i6r, I cannot recollect a single instance on modern hard drives. For sure I used to get failures on bsckimg up to dvd drive (so last but one decade).
To me verification is more of a physcological activity, these days, predicated on historical use/experience.
Naturally, there is always a SODs law that will kick in i.e. because you failed to verify it, naturally, this is the one time the backup will be knackered LOL.
Reliability of backup media is of course an issue.
Reliability of backup tools/softwares is another issue, this thread focused mainly on this issue.
There are hordes of other backup issues:
Do you have a hourly/daily/weekly/monthly/yearly backup routine?
Is your backup routine flexible enough to allow for orderly manual overrides on an as needed basis?
Do you strictly follow a 1-2-3 rule of backup (1 master, 2 backups, 3 different media) or strictly follow some other backup rule?
Do you make sure that at least 1 backup is air gapped from your live system at all times?
Do you use two or more backup tools/softwares to make the respective backups on your backup media?
How do you best integrate your backup effort in your overall computing and (home) office/house keeping?
Do you have dated and ticked off checklists for backup chores, password maintenance, and the like, and do you keep a log of irregularities?
.
.
.
Then of course, in all of the above, how do you get the overall biggest bang for your limited buck?
Each one of the '?' in the above is worth its own thread, IMHO.