Your comment was about C# being "the best language in terms of features and improvements", nothing about usage numbers.
I agree that C# is far more widely used than Scala, but Scala is being used by significant numbers of developers esp. for Spark. Tiobe is also widely regarded as a pretty poor indicator of language adoption.
Java's a pretty extreme outlier for late or non-adoption of modern features, but it is true that Java is the closest direct competitor/peer to C# in terms of usage/marketshare. C# seems to be steadily shifting from being a language which initially (v1.0) looked like Java to one which looks increasingly like Scala (e.g. addition of pattern matching, tuples, local methods etc.).
I don't think Android is a good example of a platform which .NET supports which Java doesn't since Java is the primary development language for Android apps...
I'm also pretty sure that embedded Java is widely deployed in IoT applications.
At least the JVM supports multiple languages (Scala, Clojure etc.), but if there's a spec it shouldn't be hard for anyone to add support for other languages.
The IntelliJ Scala plugin is pretty awesome too and it also offers machine translation of Java code to Scala. It's actually the most widely downloaded plugin for IntelliJ by nearly an order of magnitude. I think Kotlin is a much better option than Java, but the main selling point is simplicity for those who don't want to spend the time learning Scala (entirely valid if if that's a priority for you).
I use Scala every day. IntelliJ uses incremental compilation, so most compiles complete quicker than it takes for me to reach for the mug of coffee next to my keyboard.
Go feels more like C with garbage collection and a nicer standard library, but lacks the abstractions necessary to be anywhere near as expressive as Python, Ruby, Scala or even Rust. At the language level some advantages of Go include the fact that it's easy to learn and mostly hard to write unreadable code.