To my knowledge there are no browsers that have anything similar to brave built in. Ublock simply is incredibly well made (that’s what braves adblocker is based on), so I would always try to use that. Gnome web has in my experience the best built in Adblock except brave (fine for everything but YouTube). AFAIK Firefox forks can change what the built in content filter blocks, at least on librewolf some ads were missing even with ublock disabled.
Brave shields are based on ubo, but are patched directly into chromium so they should be immune against v3. Still going to stay on Firefox, but brave is a decent backup option. https://brave.com/blog/brave-shields-manifest-v3/