>Rails project has less functions, and with a far more predictable structure.

This is probably true if your building a very very generic small webapp. In which case, maybe use rails if it's the stack your good at.

However, as the complexity of the system grows, the less will easily fit in mvc. When that happens, pushing all the complexity into mvc will make it harder to understand, not easier.

You can do anything you want with rails. You’re not coupled to mvc. At the end of the day it’s a rack app and it’s ruby. Go wild.

You are coupled to mvc, that's the upside to a framework.

That is not true at all. You have Rails at your disposal but if you want to break free of that and use simple ruby classes and handle request/response on your own -- you are very much free to do that.

Perfect example is running Sinatra inside of Rails: https://jacobbednarz.com/posts/sinatra-in-rails

Again: ultimately you have a Rack (ruby, https://rack.github.io) webserver interface that has a Rails app mounted inside of it.

"Rails" is just some code that is running. You can choose to defeat certain parts of it, mount other stuff on the Rack server, turn rails off entirely and just use Activerecord, etc...

I do it all the time.

Sure, I wasn't defending Rails as a generally better solution.

The quoted statement tends to be true regardless!