You can't compare java to rails like this. Java is a server side language - rails is a web-dev library written in Ruby.

All the things you are complaining about have been abstracted away by many recent java and groovy libraries.

You are literally comparing some random company using a random java framework 4 years ago to modern ruby on rails. The comparison just doesn't work.

You can make java as simple as you want or as complex as you want. Modern tools like spring boot and groovy make it VERY easy to make java simple.