95% of the performance comes from the car. They fight for differences of 0.5s between drivers on the same team and that is within 99.5% of each other or something. It means results are kind of limited to a very narrow range of possibilities, the best team wont come below 3rd etc. The engineering at the top 3 is probably military industrial level for sure.

Euros also took pride of their "circuits" because it is technical, it is not about overtaking but in the old days, going to an F1 race was realy about the sound and the camping experience, again EU circuits being all in the middle of nowhere often. old Hockenheim was fucking amazing going through the forest etc. The American oval circuit experience I imagine is much closer to a stadium like atmosphere so its completely different purpose and vibe.

Both kinds of races impose limits on vehicle design. The big difference is that NASCAR is stock car racing, which originally meant that the cars had to be production models that were available to the general public. This is no longer the case, but the limitations hew much closer to that ideal.

the fans direct their racism at different people

I'm no expert but the circuits are different. F1 is driven on streets while Nascar on purpose built stadium tracks.

...as mentioned in another reply, the cars are fundamentally different (NASCAR hews closer to 20th-century stock-car archetypes, F1 closer to state-of-the-art open-wheel archetypes) and F1 is (at least nominally) a constructor's championship which competes on engineering, with all teams racing unique protoypes, while NASCAR is (at least nominally) a racing-team championship which competes strictly on drivers and tuning, with all teams racing identical silhouette cars...

...the truth is that as both series have evolved, the blend of constructor vs. racing-team competition has moved to converge somewhat toward the middle...

...the greater difference is that NASCAR is primarily raced on oval speedways while F1 is primarily raced on road circuits: the joke is that NASCAR goes fast while turning left but F1 starts, stops, and turns like real cars on a real road...

...again, though, both series have evolved to converge somewhere toward the middle: most F1 circuits are now run on dedicated racetracks which resemble twisty roads, and NASCAR now includes a few road-racing tracks in their series, too, to keep things interesting...one clear distinction is that only F1 includes real street circuits and only NASCAR races on oval speedways...

...culturally, NASCAR is the domain of american good-old-boys, and F1 the domain of european jet-setters, but there's a bit of crossover outside those core demographics...