Vivaldi is closed source, they say so on their website. I don't like the CEO of Brave, neither do I like the crypto nonesense, but arguing that Vivaldi is better for privacy (let alone vanilla chrome) is incredibly incorrect. Brave actually does a decent job of anti-fingerprinting and has strong site isolation. I prefer Cromite because it isnt associated with Brave or any crypto.
I don't dispute Brave may be private in the current version, but with all the things they did they are not trustworthy, with many write ups online, some going as far as to call it malware. You are of course free to disagree, if you don't think your browser adding extra tracking to your links is a deal breaker.
I don't know where you are reading that Vivaldi is closed source. The source code is right here: https://vivaldi.com/source/
It does have fingerprinting protection, it has blocking trackers and ads built-in, and you can enable site isolation and turn off third party cookies if you choose to.
Brave added affiliate links to URLs. While I agree this is quite shady, it is not much different from how Vivaldi makes money. Also Vivaldi is not open source and doesnt come close to Brave or Librewolf in privacy tests. Vivaldi's fingerprinting protections are incomplete (it seems they stopped at canvas randomization?), it features a weak built-in content blocker, and has an insecure default config (JS JIT and WASM are enabled). I would compare it to default ungoogled chromium + basic adblocker. Vivaldi is no where close to Librewolf or Brave in terms of adblocking, anti-fingerprinting, and browser security hardening. Vivaldi is a neat browser, but a privacy one? I don't think so.
EDIT: Here are some links. Privacytests.org is a precomputed comparison table, the other two sites are fingerprinting sites which give a better idea of how much must be protected for adequate anti-fingerprinting.
I said Vivaldi is not open source a 2 comments ago. I said I recommend Firefox and derivatives, including Librewolf, I said Brave may be more secure, but shouldn't be used for reason that have nothing to do with it. Since you are not reading my comments anyway, I won't spend the time.
Your comment I was replying to said "I don't know where you are reading that Vivaldi is closed source. The source code is right here: https://vivaldi.com/source/". I was responding to that with Vivaldi's statement about how the browser is closed source.
In your original comment you illude to it being neither open or closed source, which is not true either since it is closed source. Maybe you meant source available? I didnt read anywhere saying that.
Source available is closed source by the OSI definition, which is what is widely used and understood. The "closed" in closed source doesnt only refer to source visibility but also the freedoms upheld by open source.
Since it is source available, it isnt open source and therefore closed source.
Edit: we obviously have different definitions. I did not mean to argue over semantics. I would personally never trust a browser with proprietary code, even it is source available.
Fair enough. Yeah, I never thought of open and closed source as two exclusive options, but two of many.
I myself publish an application which isn't open source, but I publish the source code, as I believe my users have the right to know what runs on their computer, and have the freedom to audit, modify, and compile their own builds if they so wish. But I don't want someone to take and resell my application. I have yet to encounter someone calling my app closed source, but I can see how someone could.