FYI: Gemini Cli is used internally at Google. It's actually more popular than Antigravity. Google uses MCP services internally for code search (since everything is in a mono-repo you don't want to waste time grepping billions of files), accessing docs and bugs, and also accessing project specific RAG databases for expertise grounding.
Source - I know people at Google.
Have you tried it? It's like working with an idiot savant. It's absolutely brilliant, but goes off the rails constantly, spewing out CoT when it shouldn't be, getting into weird loops, spewing gibberish or repeated phrases. But when it does actually work, it's brilliant. But the issues make it unusable for dev at any level - and completely untrustworthy. Contrasted with CC or Codex CLI it's night and day. The latter two are incredibly reliable, rock solid, and crazy productive, and becoming exponentially more so by the week.