I thought it was a client computer? How can you be certain the drive was 100% the day before failure? Often the user ignores warning signs.I have never had a hard drive go from 100% functioning to zero like this before.
Anyway, regardless, I've had about 2 sudden HDD failures like yours so far this year and perhaps a dozen over my time in a small country town repair shop. Maybe my (mostly residential) customers have older computers on average.
In light of the sudden HDD failure you have just witnessed and have been assured that do happen occasionally, this argument is not strong. Backups are needed no matter what kind of storage is used, to protect against failure as well as viruses and other causes of data loss. Also it's unclear whether sudden HDD failure is less common than SSD failure, maybe not.I also do not love SSDs as many do for one of the reasons mentioned, repeatedly, in this very topic. They tend to fail out of the blue with zero warning before doing so