The plates have been blamed since the 80s. Yet drafting and the like was happening going all the way back. without plates, these cars with 100 extra HP would be in the stands and lots would die. It’s not the plates that are the problem. At least not solely.
Slow them down aerodynamically. Did you see them poking their hand out of the window during qualifying. It takes air off of the spoiler. They need to stand the windshields up. Didnt see too many people drafting million dollar Bill when he ran 220.