What's in a GGUF, besides the weights – and what's still missing?

What's in a GGUF, besides the weights - and what's still missing? GGUF is the file format that llama.cpp uses for language models. The really neat thing about GGUF is that it's just one file. Compare this to a typical safetensors repo on huggingface, where there's a pile of necessary JSON files scattered around - or to a typical ollama model, which is an OCI with layers json, go templates, etc ins...