>I really hope open-source Browsers like Firefox follow up soon with better alternatives, like on-device LLMs to counteract the "all in the cloud" LLM approach.

That's the first thing that came to mind. Every single action across every single website would be available to OpenAI with this browser. Even if I wanted to leverage something like this it'd have to be a fully local LLM interacting with a huge local DB of my info.