Eclipse was always a confusing product. It was a bastard child of Visual Age for Java from IBM, which was already a bastard of IBM's Visual Age for Smalltalk.

Visual Age for Java had some quirkiness being a Smalltalk IDE adapted to Java development (for example, the concept of a file and a hierarchical filesystem itself was definitely a second class citizen in Visual Age) and eclipse kind of rounded those rough edges.

But Eclipse became a victim of late 90s/early 2000s academic driven overengineering with overly complex/bureaucratic stuff like OSGI, and the support for the absurdly bureaucratic java development ecosystem at that time.