If data reliability is high on your list, but speed is not, use a NAS running RAID 1 (mirrored drives), so one drive can fail without compromising the data.
I used to do RAID 5 on an 8 drive array, but had a failure of the NAS motherboard. And wouldn’t you know it, they didn’t make that model anymore. No easy way to get the data back out of the RAID. I finally paid to recover the data, but learned my lesson. It’s MUCH cheaper to buy duplicate drives than it is to recover data later. If the RAID motherboard failed tomorrow, I would pop the working drive in my computer and it would just work.
Using drive mirroring pretty much eliminates the concern over premature drive failure. If it’s in warranty, pop out the bad drive and send it in for repair/replacement. The NAS will still work. Buy another drive or wait with sweaty palms until the faulty drive is fixed. Rebuild the array.