Arkenfox is great for custom browser profiles, since it’s just a user.js file overwriting and setting preferences. Since the community does a lot of the heavy lifting, you can create specific profiles for specific use cases instead of just using it out-of-the-box. For example, if you use I2P, you could create an Firefox profiles specifically for I2P by disabling JS by default and configuring the proxy settings to route everything through I2P by default.
Librewolf is great for anyone who wants a hardened browser, but may find Arkenfox overwhelming to deal with. It’s a good out-of-the-box solution that can be used by people who aren’t particularly tech savvy. Librewolf and Arkenfox have very similar fingerprints and are recognized by some tracking services, such as fingerprint.com, as the same identity.
I take some issues with Brave, given that it’s not as hardened as any of the above mentioned option and it’s relatively easy to fingerprint. I mentioned before in a different thread that you can visit fingerprint.com with the Brave browser and then open up an incognito+tor window inside of Brave. If you visit the site again, but with the incognito tor window, it will return the exact same identity rendering the use of tor useless. See here: Recommendation of FF Profile - #4 by Satoshi
If you need to use Chromium for some reason, I’d suggest just using ungoogled chromium instead.
Regarding Tor, you can use it for any day-to-day browsing and don’t have to use it strictly to visit onion sites on the dark net. There are other cases where you may want some degree of anonymity in which Tor can be useful. For example, in a separate thread I mentioned “hidden backups”, see here for more: Looking for ideas for my data backup setup? - #12 by Satoshi. Also useful, if you want create an online identity, but don’t want it linked to your real identity, although this does require some changes in behavior as well.
The Mullvad Browser is great, especially if you use multiple profiles (go to about:profiles). You can have different browser profiles each of them using a different Mullvad proxy location, thereby you can use it for specific sites and services while your identity remains the same. For example, you may be using one forum with one online identity for which you pick “Frankfurt, Germany” as the proxy location, while for activities associated with your real identity you may use “Zurich, Switzerland”. Thereby you can maintain consistency.
Generally I recommend trying to compartmentalize your activities as much as possible. In some cases you have to be consistently consistent while in others you have to be consistently inconsistent. If you are using Mullvad, it’s relatively easy since you can use a SOCKS5 proxy for each browser and thereby associate a specific location with your identities. With Tor, you don’t have to think about it, which is great for general browsing.
A reason why I recommend the above is because VPNs have come up in legal cases quite a bit. The VPN provider may to provide information on the specific user, but the government can see that you were using X VPN hosted at Y data center in Z location at a specific time and at that matches the online activity associated with your identity. You can obfuscate your activity by using multiple proxies with multiple browsers for multiple identities.
Lastly, I’m not making a case for one browser over another, since I use all of the above.