I do NOT think that a BoP is absolutely necessary, I find the classification according to LP and certain specifications such as performance and/or weight and/or tires completely sufficient. In real life there are only these specifications and certain "technical" specifications, but the coordination of the vehicle is up to each team/driver and now guess what, for example. in Formula 1, the cars of the drivers are also tuned differently.
Yes, it's more work, but it's doable over time. Also, we can expect that like GTS there will be many Gr.3/Gr.4 races and these cars are fast and competitive even with the basic setup, but with a good setup the car adapts even better to the track and the customize driver.
You need to understand how to "experience" good car setup and adjust the car to suit your driving style.
If I understand correctly, many here are still using normal "road vehicles" and these are hopelessly overwhelmed when the vehicle's performance is increased. Compare a Gr.4/Gr.3 car with a tuned road car with the same LP.
You will find that the road vehicles usually reach higher speeds and this also faster. The vehicle weight often does not differ that much, but due to the aerodynamics of a GT vehicle, it "weighs" ( Contact pressure from the spoiler ) significantly more and exerts much more "pressure" on the tires, which a road car simply lacks.
