I only use the Google models via OpenRouter. Partially as setting up directly is a pain, and keeping the Gemini CLI working was another pain but also as a buffer to protect my Google account as you mention
Could it be TPU/GPU availability? ie, is it possible that it's more profitable for their compute to be serving Anthropic models, so Gemini customers are stuck with lower compute available.
They've always been realllly slow to roll out stuff outside the org when it comes to AI. Most googlers themselves likely won't have access to this model internally.