What is the aim? People who want to get into it, but does not know how, or experts? Think half of the attraction of selfhosting is the diy aspect.

I don't disagree, and I would imagine what I'm offering would only be useful to people who are very early and don't yet know they enjoy the DIY aspect.

The aim, though, is this: I've enjoyed self-hosting. It's given me some powers that most people don't get to have who aren't also technical professionals. I'm also deeply frustrated by the environment created by the various major tech companies. If I can, I'd like to lower the barrier for people to get some of those powers without having to become experts and to make it more feasible for them to do what they want to do, rather than just what they are permitted to do.

What extra would this bring if people can just buy the parts cheaper?

Much shorter time going from "how can I control some of my own data" to "I'm running NextCloud, and its kinda like iCloud/Google Drive/Whatever Microsoft does and it's running right here under my control! Not everyone knows the path from buying parts online to having a working reverse-proxy and reasonable firewall rules. Also, standardization makes it much easier to support people, which is really what the business would be doing.

why would this be better than, let’s say a beestation?

I knew about Synology, but as a NAS product, which assumes a certain familiarity with backup schemes, etc. Kind of a prosumer-only thing. The Beestation is new to me, thanks for the tip. Quite possible what I'm proposing would have some overlap and compete with it, I'll have to read up on it.