Firefox

It is inadvisable to use multiple blockers at the same time.

Also, what you are calling "streamlined" is what I call loss of user control. You no longer have control of your content blocker, Brave does. And they've shown they'll allow content through for those who are willing to pay them. Also, I don't know if they still do it, but I remember they used to inject their own advertisements on websites (I think it was opt-out though). Honestly, Brave has done a lot of sketchy untrustworthy crap over the years and it boggles my mind that they're still so trusted by supposedly privacy and security minded people.

Finally, as others have already said, their browser is based upon the Chromium codebase that is controlled by Google and will be affected by their Manifest V3 changes.