Azure is at capacity; GH offers a lot of services for free or heavily discounted. Especially when its public repo. These aren't profit generating for Microsoft, so they are not the priority with the capacity Azure has available. GH is probably struggling with these capacity and budget constraints. They also still have some AWS and non-azure DCs in use.

Once Azure's massive spend is online things will slowly get better.

>These aren't profit generating for Microsoft

Aren't they are training their LLM on public repo, to me it's seem like a gold mine.