This has been addressed in
#154.
The current design exists in LWJGL since the first version from 15 years ago. It might be slightly annoying if you're trying to write a quick demo outside an IDE. For real applications and real OpenGL work, it works just fine. Desktop OpenGL is a massive API with a lot of complexity and having to explicitly import the appropriate classes protects against misuse.
An idea that I'm considering for LWJGL 4 is to merge classes up to OpenGL 2.1. I don't think there's any relevant driver/hardware that exposes anything less than that.
Another idea is to make GL classes extend earlier versions. Which would abuse Java and is considered a bad practice for static methods/fields.