libGDX is not in the same spotlight as Godot or Unity but still popular within Java devs circle.

I'm not aware of any resources explaining the "why libGDX" but here are some differences, speaking from my own experiences:

- Code oriented development, no authoring tool, no drag and drop, just you and the API, which might attracts traditional devs who prefer a pure coding approach.

- Very thin abstraction over the platform graphics layer, it just adds a few more drawing APIs over the underlying graphics API (OpenGL and WebGL). You’re free to build your own abstractions on top of the core APIs.

- Java, while might be verbose, is very stable, easy to learn and has huge ecosystem. Or you can just use Kotlin.

- Once you learn the ins and outs of the framework, it actually has a greater sense of freedom compared to Unity, Godot, Unreal, etc because those engines always force you to do things in their own opinionated ways.