Java programs, however, tend to be very large and sprawling code-bases built on even bigger mountains of shared libraries. This is a product of the language's simplicity, the design decisions present in the standard library, and how the Java community chooses to solve problems as a group (e.g. "dependency injection"). This presents a big learning challenge to people encountering Java projects on the job: there's a huge amount of stuff to take in. Were Java a spoken language it would be as if everyone talked in a highly formal and elaborate prose all the time.

People tend to conflate these two learning tasks (language vs practice), lumping it all together as "Java is complicated."

$0.02: Java is the only technology stack where I have encountered a logging plugin designed to filter out common libraries in stack traces. The call depth on J2EE architecture is so incredibly deep at times, this is almost essential to make sense of errors in any reasonable amount of time. JavaScript, Python, PHP, Go, Rust, ASP, C++, C#, every other language and framework I have used professionally has had a much shallower call stack by comparison. IMO, this is a direct consequence of the sheer volume of code present in professional Java solutions, and the complexity that Java engineers must learn to handle.

Some articles showing the knock-on effects of this phenomenon: