Short answer: For Gmail-heavy lean ops, use Gemini (Google Workspace) when you want native Gmail parsing, in-context summaries, and fewer external dependencies; use Zapier when you need broad third-party integrations, visual routing, and easy filters. Gemini simplifies summaries and keeps data in Google; Zapier wins for multi-app automation and templates. For a quick compare of generative assistants, see: Compare ChatGPT and Gemini