Play is for Scala and Java too. Vaadin does much more than charts--although its wrapping of highcharts is pretty nice--and is quite pleasant if you'd rather write Java than HTML and its close relatives.
I guess from the Java perspective, Javascript does not look too sexy, as it is a small but dangerous / unhelpful language with an uncompetitive-to-Java library ecosystem. TypeScript is great however.
React, Webpack, CSS compilers and pretty much all other modern frontend (compile-time) asset tools are running on Node.js and install from npmjs.com. Node.js is also perfect for a shallow web-facing container developed along with the front-end as a complement to Java-based (mini/SOA/whatever)-services. So I think it's quite useful to make Node.js workloads run under the JVM.
When we talk about rich libraries we mean actual libraries for generating PDFs, reading barcodes, report generation, talking with all kinds of enterprise databases, GPU programming, parallel distributed algorithms, embedded development...
Not yet another packaging tool or fait-divers like pad left.
And the majority of them written in pure Java, not C++ wrapped in a JavaScript API.
How do you generate a PDF on such a cool JavaScript front end application?
Hint, you don't. Just hope that the browser does a good job with print to PDF, or run a server side pile of shell scripts, using LaTeX and Postscript, instead of a plain simple library.
And this is just one example from many, where JavaScript/Web sucks on the front-end.
I guess from the Java perspective, Javascript does not look too sexy, as it is a small but dangerous / unhelpful language with an uncompetitive-to-Java library ecosystem. TypeScript is great however.