I don't disagree with anything any of you have said, but do notice that fans are much more brand-loyal than racers. And that matters. While I don't think the sky is falling, I do think some classes have an overabundance of one body style.
In the late 70s I went to an IROC race, which ironically in those years was all Camaros
For those who don't know, IROC racing features one model of car, identically prepared, with the only difference being the drivers. But being a drag fan and not really familiar with the road race drivers my choices were to root for either a name I had heard of somewhere, or, "Oooooh, that one is a nice shade of blue. I'll root for him." My point is sameness is neither interesting nor engaging.
Yes, there is an ideal aerodynamic form for each class, although I'm not convinced the Camaro is it. The prevalence is more because racers in general tend to be more often followers than innovators. "Hey, that guy is winning with brand X. Let's do what he's doing." We saw this happen in NFC when the "Big Show" version of the '69 Camaro was released and won CHRR right away. Many cried foul saying it is not in the spirit of nostalgia racing, and I agree. But the body was not outlawed and the result has been a higher percentage of '69 Camaros running in NFC now than there ever was in funny car racing of that era. To be sure an internet search of period floppers will find some Camaros, but it was not disproportionate to the number of different brands and bodies out there. With probably a dozen different body styles
everybody had
something to root for. Now I hear fans saying things like NFC means 'Nother Freaking Camaro. That's not good for the sport.
While evolution towards the ideal form is going to happen, it's not necessarily the best path for the sport. For example, FC has three brands but once you remove the brand identifications they are homogeneous blobs. Turns out the blob is the best form for cutting through the air. But that leaves newcomers in my IROC predicament. Root for the name you heard of somewhere, or, "Oh, that one has cool graphics."
Part of what made drag racing great was variety. As the French say, Vive la difference! Although they were not thinking about drag racing