Please MS, increase development resources behind net and c# instead. It will benefit Java more than direct Java development - competition will give Java more motivation to grow.
They are adding to the language, which is a mixed blessing, it is helping in some aspects, but also making the syntax even more complicated to a beginer. But the standard libraries are rather stale and would deserve a lot more love.
C# with .Net should compete with Go and rust these days, fight for the mindshare of developers.
I think Mads Torgersen & co. are doing a wonderful job.
We've had a new version of C# with each new (recent at least) release of Visual Studio.
Did you have issues with the quality of new features? I'm really puzzled by your comment.
Besides apart from C# there's also CLR and Jit that could use more love. It is well known that jvm is a better vm than CLR. Most of the CLR speed comes from using references to value types but somewhat as an afterthought and without tools that C++ provides (readonly gives you muh less power that const reference).
Apart from Borrow Checker which is a recent invention, all programming languages features, as far as I am concern has been done previously in one way or another. There is only so many language features you can fit in on a languages like C# which is soon to be 20 years old. It is a sign of maturity. And C# in itself is already very modern compared to Java.
Most of the JVM performance improvement came from many Enterprise customers absolutely pushing the limit to a point where performance of JVM today would be unthinkable 10 - 20 years ago. It is the work a hundreds of millions if not billions over the past two decade. And it is not like Microsoft are not doing research on how to speed it up.