When building a device primarily used for storing personal things, I'd much prefer to save money on the motherboard and risk that failing than skimping on the drives themselves
How do I know? I've had two drives and one MB fail in quick succession thanks to a silently failing power supply.
Motherboards have fried connected hardware before, poor grounding/ESD protections, firmware bugs together with aggressive power management, wiring weirdness and power related faults have broken people's drives before.
What I've never heard about is a drive breaking something else in a system, but broken motherboards have taken friends with them more than once.
I’ve experienced many drive failures over the years, but never lost data due to RAID. Failing MB or PSU on the other hand has wiped out my entire system.