The argument that "Google still controls Chromium so it's not good enough" is exactly the kind of FUD I'd expect to back up this kind of psyop, too.
If not, then no, switching to another chromium based browser is not enough.
And fwiw my experience trying Brave was that the user experience was actually more different from chrome than Firefox.
I suggested that MV3 would be a big nothing from the beginning. And people on HN argued with me every step of the way (mostly people in the latter category who refused to do even the slightest bit of research or verify that the people who they were parroting were actually reliable reporters of anything at all).
Now that MV3 is here, we can see this. MV3 is here. MV2 is gone. And ad blocking still works.
I just installed Google Chrome, clicked on some YouTube videos, and verified that I was getting ads. Then I installed Ublock Origin Lite, and the ads disappeared. I no longer get display ads or video ads on any website.
Now, if you want to bring up some edge case or something, be my guest. But for 99% of even ad block users, strictly speaking, blocking ads is more than enough.