[wolverine876]

The 'same' extensions on each browser control for your experience, but not for the browsers' performance:

The browsers have the same or very similar APIs for the extensions but that is just the interface; each browser executes the extension's instructions differently (a lot or a little - I don't know the browsers' code). The same extension will impact Brave's performance differently than it will impact Firefox's. In other words, the same extension is not, in this sense, the 'same' on each browser.

In this sense, an extension is part of the user experience, like a website. The Speedometer test suite doesn't include those extensions (I assume) and that is the experience the browsers are optimized for.

The parent's test doesn't represent that; it does represent their desired experience, of course.