Questions about MCP or ChatGPT Apps?

Questions about MCP or ChatGPT Apps?

What is MCP, and how does it differ from traditional APIs?
Why should I adopt MCP if I already have APIs and a frontend?
How is MCP different from function calling or plugins?
How much support is there for MCP?
Is MCP production-ready?
Why use a hosting platform? Isn’t deploying an MCP server easy?
How do I measure ROI on MCP integration?
What is the OpenAI Apps SDK and how does it relate to MCP?
What makes the Apps SDK a major step for AI developers?
How do developers build and deploy ChatGPT Apps with MCP?