I think opening up the 2021 rules a bit to allow more design freedom is the way to go! That's what i was thinking if the teams don't agree with more standard parts and design! Well big teams will always disagree to any big change...
Ground effect and smaller-simpler wings together with better tires (if Pirelli manages to make them at last) will make the cars instantly better in following one another! So there's no need for "GP1" cars...also some kind of budget cap and better distribution of the money given to the teams will help smaller teams a bit!
And for God's sake...get rid of the Ferrari veto and the 100M $ given to them just to be in F1...better distribute this kind of money to the smaller teams to help them get better!
Help Williams at least..it's just silly for the sport, seeing them so much behind everyone...they are also a historic team after all!! (Just joking here)