FWIW, Brave still supports manifest v2 and the full version of uBlock Origin. Chrome has uBO Lite since they only have manifest v3 now. Firefox and LibreWolf don’t have to deal with this, and still support the real uBlock Origin. I’m not sure what exactly Brave “shield” is doing, but I think if you use EFF’s privacy badger on Firefox and block third party cookies, you are getting the same thing.