I would say, for most “regular users” (meaning someone who’s comfortable but not the tpope of emacs), you’ll be fine with most layers. Layers being the set of packages and settings for those packages that make up what you add to your config file.
As an example, if I want to edit ex-files I’ll add elixir to my layers and restart, which will install a pre-configured set of packages and customizations for those packages, these being aimed at Elixir editing and tooling. This is the abstraction you’d create when you were setting something up for yourself and it’s not a completely horrible experience, even in the cases where spacemacs is missing something. Before you get to that point, most layers will already be set up reasonably for you.
The anectode you wrote would be pretty much the same for spacemacs in that you’d be able to add any additional customization that pertains to your user-config in your config file as it is has both dotspacemacs/init (executed before loading of packages) and dotspacemacs/user-config (executed after loading of packages).
