OpenAI had a first mover advantage. ChatGPT has a good interface and GPT4 still leads on many benchmarks. But it continues to get worse and worse and others are catching up with significantly lower parameter counts. Their moat is shrinking very quickly.
Llama2 is an open source meta model, btw. Anyscale's ray makes it much easier to leverage the super fast pace of development in the OSS community (or released by large companies as OSS).