Actually, aren't all browser extensions a security nightmare? Or has something changed recently?
No, because a typical safe-to-run browser extension is written in such a way that it can be examined to see what it does. AI-based tools can’t be analyzed based on their code, so the only way to make them safe is by limiting their capabilities. Any such capability limit is likely to be either too constraining, not constraining enough, or require as much planning ability as the AI itself.
Without this feature, extensions will keep insisting they need access, and the user will eventually fall for it.