I found out that if you go to brave://flags and search for ANGLE graphics backend the “Default” setting is what slows down brave so much when you have hardware acceleration enabled. I switched it out to “OpenGL” and a big performance difference. The Default setting that Brave is giving everyone is probably outdated and slowing down many people.
Also try D3D11ON12 it also may work better than “OpenGL” experiment with these two values and see which one gives you better results as results may vary from system to system.