Western Digital offers the most reliable high-capacity hard drives, with Annualized Failure Rates (ARF) of under 0.35%. Or so the latest quarterly data from Backblaze indicates. The drives include the 14 TB and 16 TB models that have been in operation for 8.537 million and 5.139 million days, respec...
Not sure that the failure rate is all that important anymore because in the first instance most people are running SSD's as their primary drive and secondly who stores bulk data on solitary hard drives?
With easy to use filesystems like ZFS, I store data using Raid-Z (raid 5) or Raid-Z2 (raid 6) which is a bit more expensive, but it means a single hard disk failure is no longer a case of catastrophic data loss.
If you're going to be running a Raid-Z/Z2 stripe in your NAS and you're given a choice of buying hard drives with a 2% AFR or alternatively a different bunch of drives that have a 1% AFR but cost say 10%-20% more then which do you choose? Since you no longer have data loss with a single drive failure so then it's just an economic decision of which is the greater cost of either dealing with extra RMA's vs paying more upfront.