Over the years I have built several Single Page Web applications (SPAs) using frontend frameworks such as React and Angular. But recently, I was building a web app with Rails I started thinking about the following:
Rails is a great tool for solo and small team developers because it's really just a lever. It gives you and the team the fulcrum and beam to deal with the same set of problems as a larger team by providing a simplistic mental model through which to reason about the software application.
Let's trigger some software puritans on both side of the aisle and bring up the heated "SPA and Backend JSON Api" versus "Server Side Application" debate. This debate is not really a technology problem, but, rather a personnel problem.
Figure: Frameworks linearize difficulty of understanding the model