which brand? Anytime you have data locally it is lot of work. There is a reason people go to Google drive or even proton drive etc for that reason. If you can do that initial setup then DIY is not worse. Yes, all these plug-n-play give a false sense of security. One of the RAID drives is failing - no one knows.

Your definition of fiddling is maybe wrong. Not everyone is Linus S or Jeff geerling to look for that exact DDR stick etc. Get a resonable laptop or mini PC with 2 x drives. Done. Even windows drive share.

storage of data long-term of course to many segments of a market needs to be seamless and safe feeling, comforting even. To slap a brand on the side of a NAS that is complex and causes grandma to lose the entire family photo history that you scanned for a few summers after your uncle did research for decades - well, that's not great for repeat sales, right?

Why are you comparing a laptop to a NAS?