Bookmarked https://torquemag.io/2016/11/singletons-wordpress-good-evil/.
> Singletons are useful, but they reduce flexibility and therefore should be used sparingly. EDD is a great example. There is one main singleton that houses all the other “main” instances, of the other classes, without having to use a singleton on every one of those other classes.
One response to “Bookmarked https://torquemag.io/2016/11/singletons-wordpress-good-evil/. “Singletons are useful, but they …”
That looks like a somewhat appropriate trade-off between being able to still retrieve a (single) class instance (like, for removing callbacks from hooks) and testability.