Java might be the most successful programming language. It is a solid choice among many different fields. It is used on huge infrastructure projects (Apache Foundation), governments, big tech companies such as amazon, ibm, google, apple for many large scale services. It can do web, ml, GUIs, it's still strong among academics. On top of that it offers a great programming experience with excellent IDE support and it's…
In my opinion, Java as a web language is good when you don't need to really understand what's happening (like in low-traffic situations). If concurrency isn't an issue, then the massive amount of libraries can help you a lot. In high-traffic environments, that ignorance punishes you. I've always felt Java and the JVM are of the mindset that you need a Ph.D. to even understand how it works or how to configure it, and…
I've seen the same troubles with alternatives, just without the amazing tools, featuresome standard library or widely-accepted conventions.
Erlang is amazing and is places concurrency in a more central position. I'm hopeful Project Loom will greatly diminish the gap while carrying legacy code forward unchanged.