This summarises my feelings so far precisely. Alas, I’m not quite sure it’s possible to have this: the easier and more full-featured something is to use out of the box, the more components it needs — or at least, its components become more complicated in and of themselves.
One alternate approach I find interesting is that of NixOS: everything is declaratively specified in a single place, so it’s easy to configure stuff, but also easy to see how everything works. I actually tried out NixOS before installing Arch on the aforementioned desktop box, and if it wasn’t for the sheer opaqueness of Nixpkgs I’d still be using it. On the other hand, I can hardly call Nix ‘simple’… as with everything, it’s all tradeoffs, I suppose.