There's no need to toss the drives at three years. Run drive diagnostics on them using a tool (GSmartControl, WinDLG, Hard Disk Sentinel, etc). Ideally every six months full scan, at least once per year.
Drives easily can last ten years without issue, and the odds of all drives failing simultaneously is near-zero.
Really you should keep at least one, ideally two, drives at different locations. And add an encrypted cloud backup to the mix.