Great tool for documenting your setup. I use this at work a lot

Crysis 2 doesn't fit the 10 year timeframe OP mentioned ;)

I would say that "on prem" defines a location, "selfhosting" an action. You can do both at the same time, e.g. selfhosting nextcloud onprem.

Apparently, it is not only my oberservation, but the article says similarly:

The inconsistent approach to backward compatibility in decades past may also have played a part.

However, I'm not a db admin and my perspective might be biased (infosec).

I would say that this is a sign of a bad product. Apparently, compatibility between SQL server versions is not great.

Probably overkill, but for projects like this I've setup WordPress in the past. Once everything was done, I converted the WordPress page to a static site with httrack and use the static version.

This gives the ease of setting up and editing combined with the stability and security of a static HTML website.

While you can probably use them for some small tasks (like a switch, a file server with a USB thumb drive or a print server), you're probably better off if you can sell them and buy a raspberry pi or similar.

The Fritzbox 7530 for example could be sold for 50€ (at least in my country).

That's exactly what the nextcloud desktop app does.

What I don't get is why anyone would like to buy a new gadget for some AI features. Just develop a nice app and let people run it on their phones.

TBH, the description in the original post is not very clear.

Have you tried the official Nextcloud desktop app?

Many "smart" devices are sold with the idea that you can control your home from somewhere else. Maybe change the temperature on your way home or get notified when someone rings your doorbell. All this stuff requires servers to work.

Controlling some lightbulbs via bluetooth/wifi would be possible of course, but probably not very interesting for many.