An oval track is meant more for NASCAR. Even Indycar shouldn't really be running any oval races except the 500 on their schedule. It doesn't showcase what those cars can really do. No other car can corner at 150 mph. F1 proves that the hypothesis and laws of physics and aerodynamics are correct. F1 isn't made for oval racing, just like NASCAR isn't made for road racing. Also, F1 will have a hard explaining the car that flew into in the grandstands due to downforce. Also, assuming that the track is banked, causes issues for the tires (2005 F1 U.S. Grand Prix of Indianapolis). Also, how would an oval track get a FIA grade sanction? The only benefits are way more overtaking, more exciting racing, and possibly a higher attendance turnout.