it's just a black box, plugged into a bigger black box - accessible through lan or wi-fi depending on my mood, no raid, no redundancy - just very expensive meticulously tested  high quality drives, if they are not high quality, then don't swallow - return the drives and demand to be compensated - if you play your cards right they'll accidently give you a drive better than the one you actually paid money for -
rinse, repeat, recycle drives every three to four years, or until you have room for another big black box

Raid is useful, but it's not the magic bullet everyone makes it out to be, and going for full 'proper' data retention is stupidly expensive and should be reserved only for data that you cannot live without, like
your diary, tax documents, etc I'd be sad if one of these drives failed and took all of my anime and Youtube videos with it, but honestly, if a video gets removed and I can't simply redownload it, the video creator didn't give a shit  so id have to get over it