You seem to be equating frameworkless with library-less.

> a team that spent weeks on "given a certain event happens in the software, dispatch a notification to the user".

This is trivial without a framework as long as there is a library you can use to "notify the user" (e.g. an email or chat library). It's actually easier without a framework because "event" is just a line of code somewhere in your own application, while in a framework, it can mean a million things and maybe NOT what you actually wanted.