It's true the JVM has a large ecosystem, but the .NET one is still pretty substantial. I would also argue there's a fair bit of innovation in the .NET Core world :)
They need to make it more visible if there is! I think it's pretty rare to see a .NET paper. I can't remember the last time I saw one, where there are tons of major JVM research projects.
The language itself is incredible, and just keeps getting better and better with every release.
It'd be neat to see people turning to .NET when writing those kinds of systems, but maybe it's just not cool enough in the Bay Area.
This is in contrast to the JVM where Java is showing its age, but mountains of work poured into the JVM keep it performant: OpenJ9 and Hotspot, Project Loom, Zero GC, as well as big non-Oracle investment such as Shenandoah GC contributed by Redhat, etc.