> To my understanding there is no data sent from my Brave client to any Brave servers.
That would be wrong. By Brave's own confession, there are 70 requests it sends "home" on startup [1]. Regardless of request payload, each of them contains your PII (IP address at the very least). There is plenty of opportunity for your data to be stored and used (not saying that it is).
If and how is that data actually used, we do not know, because this part is closed-source. When companies that are running advertising-based business models like Brave and Google are in question, this is the most important part users should be concerned with. Only way to settle this would be if the browser actually sent no requests anywhere, like you initially believed to be true. Indeed, a web browser has no business making requests anywhere without my explicit approval!
> It’s possible to know that by looking at the code for Chrome. Brave doesn’t do this and it’s possible to know that by looking at the code for Brave.
Do not want to be harsh but I assume you didn't actually look into the Brave's source code. You could have, but in reality very few actually do. Open-source "tag" on software can give this false sense of security because you rely on someone else to do the hard work and actually look through millions of lines of code.
The only way to actually trust a browser from a privacy standpoint is to check if it is indeed not transmitting any data. Instead of relying on source code, a much easier and foolproof way to check this is to use a network proxy, many are commonly available for all platforms. Then you can believe your own eyes vs marketing.
Disclaimer: I am in the business of creating a privacy respecting, zero-telemetry, browser. This topic is near and dear to my heart. More on this here [2] and here [3]
[1] https://brave.com/popular-browsers-first-run/
[2] https://browser.kagi.com/faq.html#ossprivacy
[3] https://browser.kagi.com/faq.html#privacy