BeamNG Traffic, Game Engine Bottleneck

Hi all, i came across this video a while ago:

You can see that the CPU (Ryzen 9 3950x with 16 cores & 32 Threads) can handle 10 cars easily.
As soon as he spawns in 20 cars though, the performance drops significantly, but neither the CPU nor GPU are being utilized to their maximum potential. In fact, the GPU had even less usage with 20 cars.
It seems like there is a bottleneck with the game engine, as the CPU has way more potential, but it´s not being used when needed.
So, is it even possible to make such optimizations to BeamNG? I just feel like this will be a huge thing in the future; PC´s become more and more powerful, and maybe their hardware will not used to the full extent.

For example, there are already very resource heavy vehicles like the CrashHard BigRig, which have a ton of nodes etc., but the performance is just terreible on most computers. For me, BeamNG runs at 20fps with the most resource-heavy BigRig, but neither the GPU nor CPU are being utilized more to compensate for the low frame rate.
This also is very important when the crash physics get improved sometime; But for now, it´s probably bottlenecked by current BeamNG, as seen above.

Thanks for reading!
I´d be happy if someone who knows more about this topic or maybe a BeamNG developer can answer to this