I think that when GP said, "ecosystem is over-engineered", they didn't mean that it's too rich, they meant to say that it's over-engineered.

Which, I'm not sure there's a more durable reputation in all of informatics than Java's reputation for over-engineering things.

There are cleaner Java libraries for most things nowadays, but the culture around the language is also such that, in many companies, it is politically much easier to use another language entirely than it is to use Java but choose a REST framework that doesn't implement JAX-RS.