SSDs didn't really change anything, other than adding a few interesting catastrophic failure modes when their firmware goes AWOL. Mass storage drives are always unreliable, and have been since they were first invented. Stuff on them is nearly always valuable. Therefore you have a decent mirroring / backup strategy, with recovery time dependent on the value / importance of the data.
XPoint won't change that - data loss is almost never an option, and even if the drive doesn't fail, the building might get hit by lightning, catch fire, etc ... so you still need backups and second drive.
Honestly there isn't really a distinction between a good drive and a bad drive - the difference between 99.99% and 99.999% reliability is immaterial if your business *relies* on that data you can't afford to be the people in the bad luck zone (either because of bad drive, act of God, or human error).
> as fast and reliable as the 3D XPoint is going to be.
Reliable. Irrelevent - see above.
Fast - either provide data, or sit quietly and wait. We've been promised the "next big thing" in both DDR and HDD replacements for at least the last 20 years. Most of it is expensive vaporware which never gets out of R&D and into mass production; even if the numbers are great, if you can't mass produce it on cost and with high yield then it's DoA.