Initial release 2005. i.e. Young.
How could a 12-year-old framework not be old enough for you?
The issue is that you wont do good frontend in it (obviously), java programmers are more expensive, learning it well enough so that you can actually be that fast takes a lot of time and hosting is way more expensive. Learning language itself is easy, but absorbing necessary frameworks takes time. Moreover, people who are good in frontend prefer languages similar to javascript, because they already know it very well so those are easier to learn for them.
I think this is why it does good in enterprise - they have money to throw at hardware, most projects are under huge time pressure constantly and requirements change constantly. Frontend is super important for product, but not so much for enterprise.
After that, you'll understand that Java is on the spectrum of "easy" programming languages.
The IDEs are very helpful by the way. You only need one SDK, which is a single download.
But yeah, learning java ecosystem well enough takes a lot of time for someone who is just starting and you have to be comfortable with abstract thinking.
If you want faster or lower level, you gotta move to C++, which is uber-hardcore in terms of non-simplicity and impossible-to-learn.
If you want easier, you gotta move to python/ruby/node.js, which are a joke in terms of performance and concurrency, with the last 2 being fairly young and immature (< 10 years).
Either way, the tooling sucks compared to Java, if not entirely non existent.
Entreprisey development is on Java because that's what best for them. Web development is on something else because they pick what's cool and trendy.