I've never been a Java dev, but as I understand the package manager story is/was really bad. I've always wondered if that's part of the reason why you see so few open source efforts compared to other languages.
When I've used Scala, package management was hell. When I've used Node, there were a million warnings about the dependencies of my dependencies whenever I installed something. Upgrading often broke things contrary to Java. Plus many dependencies went dead over night. When I've used JS libraries in TS, many integrations/adaptors where half baked and underdocumented.
I'd say the best dependency management I've used is from Rust, but Java was no problem, even with Maven.
The ecosystem might have changed since I've left, but there were many well maintained libraries and frameworks for Java, Apache, Spring and many more. What Java lacked were some higher level frameworks back than, E.g. ready to use payment frameworks (you had to use lower level frameworks like E.g. what Stripe supplied as a library).
Java has excellent package management and there is a giant ecosystem and excellent libraries for almost everything you can think of.