>>there are several contenders these days that I would say might fit those criteria

Even if you get the basic 'Batteries Included' part right, you still won't match up ubiquity in terms of being able to hire developers(in big numbers), common knowledge base, maintainability of code bases. Java code bases tend to be around for long. And people of all skill levels can get started with minimal handholding.

Also note not all companies have the revenue streams of top internet companies. And they can't afford to flush hundreds of millions of dollars, and man years of personnel time down the sewers to arrive at hiring the perfect candidate for the job. Almost always most companies need candidates who can get job done, for whatever salary they can offer. And they can't afford to rewrite their code every two years, so they care deeply about things like easy hiring, and code maintainability on the longer run.

Apart from these things Java itself is a great piece of tech, and has passed the test of time over so many technology trends.

If you are starting a backend project, Java is more or less the best and the top tech choice at this point, and has been for long now.