Depends on what you're building. Rails/django/heroku are web app accelerators. If you are building a web app, then yea they make it super easy and take away a lot of having to think about complex systems, but if you're building anything else not really
Are you sure about that? You get a ton from a batteries included framework, but it doesn't prevent from successfully building a complex system, nor does it preclude you from having to reason through the powerful footguns.
The way I'd describe it is that /most/ codebases can fit into what you'd call a "web app" including most codebases that include complex systems -- there are, of course, significant exceptions.
