java has issues, too. i'm not talking about the language per se, but the whole situation. the end-user java experience sucks, most people know it mainly for requiring updates, making browsers insecure, and using ungodly amounts of RAM. in a world with containerization, the write-once-run-anywhere marketing line isn't so interesting anymore. groovy, scala, clojure, and kotlin injected some cool ideas, but might have done more harm by cannibalizing the community and proving that just because it runs on the JVM doesn't make it great (to some people :)).
we agree it isn't going anywhere fast. huge corporations use it daily still which means huge paychecks. but getting by isn't the same as thriving, and i think it's a valid question to ask. because just like C#, simply adding new language features isn't always enough.