I personally choose Java/SpringBoot, it has a steep learning curve, but has strong typing, runs as fast as most C++ code out there, plus you can do async.
and if you want something fast but that is as easy as Rails and runs on Java/Groovy/JVM, use Grails.
That doesn't seem easy at all. Immediately I am presented with 5 choices and then a list of 50 things that I might want to add to my application. Some of those 50 choices seem to be mutually exclusive and I don't have any way of knowing which I might want or why.
Rails? Just rails new myapp.
Build system, Language, Spring version, Java packaging, Java version
The rest is naming.
That is not complex to me.
As for the dependency options... well, they are dependency options. I'm sure you have no problem with adding gems to a rails project, even though there are thousands of them that may be mutually exclusive! A non-ruby dev might not know which gem they want and would have no way of knowing what they want or why!
rails new myapp is exactly the same as doing this with no dependencies.
Is there a reason you'd use Grails over Rails on jRuby?
Note: I see that torquebox was discontinued. It was a simple way of getting your rails project to work with JBoss and had many nice utilities like infinispan and stomp. Good old days.
It's not a perfect replacement, but it can save time if you are starting a new project with a lot of boilerplate code.
I've used RoR for 5 years, spring boot/kotlin for 2 years and Django for a year. Once you've set up the workflow, there isn't much difference in terms of productivity. The pain point is setting up the base project and keeping it updated as library versions change.
What django and spring boot are missing are the commandline generators for entities, controllers and views and a quick setup.
Django and spring boot need a little bit of careful setup. Django needs its settings, applications array, middleware declarations, etc. Once you get over this and start adding your entities, views and routes it goes fine.
Spring boot requires a rigid folder structure, application property files, a careful setup for migrations and logging. Liquibase setup, etc. It doesn't get off the ground easily. Once you start writing your entities, repositories, controllers, services, views it goes smoothly thanks to lazy initializers.