It's far better to use this site: fingerprint.com/demo
they are one of the largest actual/commercial vendors of fingerprinting software. their business is to track you.
please try it with brave and post your results. i could be wrong but last time i checked brave failed this test. arkenfox doesn't even allow the tracking to load which I consider a pass although you could argue that just because the results don't load doesn't mean they aren't able to track you in some way
I've been using Firefox on desktop and mobile exclusively for a number of years now. I will say the experience isn't perfect but it's better than using a browser made by a company that is actively hostile to its users.
It is important to take note that you will experience issues with some websites. For example, https://astro.build/ Try scrolling quickly up and down on this page on Firefox vs Chrome (on mobile).