With .gmi files or "gemini://" URLs and a compliant Gemini client, I don't need to even need to load the document beforehand to know if it intends to execute code on my device or not. It already won't by design, it won't in the future, and it doesn't require settings management, vendor whitelisting, popups, or caring who makes the browser for me to make it behave that way.

Whereas that .html document with it's noexec meta tag might be updated in the future to suddenly contain code.