A big reason things like side skirts and vacuum cars were banned was that those technologies were very good at making downforce, until you hit a bump or curb big enough to break the "seal" between the car and ground. Then most of your downforce went away in an instant. Not a very safe thing.
Yes most of the regulation changes in the last 20 years have been focused on taking away downforce b/c without constraints the engineers could design cars that would corner with such force the drivers would be on the verge of blacking out.
The other focus is to try and make passing easier. When you depend on downforce for grip and you get right behind another car, in their air wake, your downforce goes down b/c not as much air is going over the wings. Your grip goes down and you can't pass that car.
Yes most of the regulation changes in the last 20 years have been focused on taking away downforce b/c without constraints the engineers could design cars that would corner with such force the drivers would be on the verge of blacking out.
The other focus is to try and make passing easier. When you depend on downforce for grip and you get right behind another car, in their air wake, your downforce goes down b/c not as much air is going over the wings. Your grip goes down and you can't pass that car.