I have to mostly agree w you on this. The modern jets are featureless pancakes having no character or differentiating outlines. Contrast them to some of the jets you mentioned. Unfortunately, this is what aerodynamics and stealth has rendered. Although I am not much of a "jet" guy, it's hard not to like a Harrier or Me-262. But while prop driven planes have the most class, few modelers want to deal with rigging or, perish the thought, lozenge camouflage and spoked wheels.
Aerodynamics and ease of production have also shaped modern cars, all of which wind up looking the same as a result. Furthermore, these days, they are little more than "laptops on wheels". Broken hard drive? Throw the car out and buy a new one. Even Porsche and Ferrari are little better, producing cars that look either like rounded blobs or transformers.
And last, motorcycles have fallen to the same level as cars these days, having too much unneeded and underutilized technology, transformer like bodywork and too much weight. Contrast the new bikes to a Ducati 916, a Ducati 750 Sport or maybe even an 80's BMW aircooled twin.