Rails isn't the fastest or the smartest framework. It has weird choices, confusing aspects and some downright terrible defaults, but for me at least, it is the
best framework and it has been for years for one simple reason: DOCUMENTATION!
Every few years or so, a bunch of these articles come out shouting from the roof tops, "Rails is dead!" and "Long live Rails!" They often like to praise some new framework, like Hanami, as the answer to all our woes, but they never seem to address documentation.
In my opinion, documentation is where Rails blows every other framework away. I have never been forced to read Rails' source code to understand how something works (I have read some of the source, but for fun, not out of need), and I can't say that about any of the other framework I've worked with. There's always some obscure method or class somewhere in them that does something unintuitive that I always have to look up. In Rails, finding the documentation on that method is as simple as a Google search, but in django, expressjs, or any of the others I've encountered, that documentation usually doesn't even exist at all.
Efficiency, scalability and reliability are all great, but when I'm starting a web app from scratch, they're really not that important. I can worry about those things once I have funding. In the meantime, I only need them to be good enough, and Rails defaults are usually good enough.
What I really need when I'm starting a new project and I'm working on a shoestring budget, is speed. I need to build something fast so I can get funded. Once I'm funded, then I can think about implementing JRuby or splitting code out into microservices or rewriting with another framework, but by then, I'll have the money to take my time. Until then, Rails is the perfect framework for me and I'll keep using it until it's not.