Somehow gemini-cli is so janky and doesn't get the latest models. But Antigravity is the new golden child? Just have a great suite of predictably quality products.
It's the vercel way. There have been plenty of experiments leading up to this (even by vercel employees before they joined) but re-packaging it as "the" solution, rather than just a tool renderer from props (tool schema)
OpenAI seems to limit how "hard" your gpt-5-codex can think depending on your subscription plan; whereas Anthropic/Claude only limits how much use you get. I evaluate Codex every month or so with a problem suited to it, but rarely gets merged over a version produced by Charlie (which yes is $500/mo, but rarely causes problems) or something Claude did in a managed or unmanaged session. ymmv
It's a really good platform for Typescript microservices which scale-to-zero (up to very high theoretical limits), but it wouldn't be a platform you'd migrate a monolith PHP app to (for example).
You're describing why reasoning is such a big deal. It can do this freakout in a safe, internal environment, and once it's recent output is confident enough flip into the "actual output" mode.