"Apple Intelligence", at least the part that's available to developers via the Foundation Models framework is a tiny ~3B model [0] with very limited context window. It's mainly good for simple things like tagging/classification and small snippets of text.
[0] https://github.com/fguzman82/apple-foundation-model-analysis
Yes, but the Foundation Model framework can seamlessly use Apple's much larger models via Private Cloud Compute or switch to ChatGPT.
When macOS 26 is officially announced on September 9, I expect Apple to announce support for Anthropic and Google models.