Comment by spleen

Point taken. I was actually referring to concepts that do not come out of thr box with Rails.

For example, it promotes use of concerns, which can easily go out of control. Then other people come with singletons, interactors or service objects.

Or, like Minitest, which is fine to begin with, but the sooner you switch to RSpec, you will be better off in the long run.

In my experience, these kind of tooling options tend to fire up almost religious discussions.