A race car has completely different characteristics compared to a road car even tho they are both in the same car class so when we race street legal cars against race cars in open lobbies it creates very non-homogeneous races where the road car is faster on straights but much slower on corners which creates a huge disadvantage on grip heavy tracks and makes it impossible to win certain races with a road car.
So race cars must be in separate classes from road cars to create more homogeneous and realistic races like in Project cars 3 where there is “Road” series for road cars, “GTA” for GT3 cars, “GTB” for GT4 cars etc…