Last time DARPA flew something at 17,000mph within the atmosphere, didn't it just sorta fall apart in the sky? And once you're moving that fast, aren't you more

Last time DARPA flew something at 17,000mph within the atmosphere, didn't it just sorta fall apart in the sky? And once you're moving that fast, aren't you more just destroying all the air particles instead of moving them so it's not really aerodynamics? https://en.wikipedia.org/wiki/DARPA_Falcon_Project https://en.wikipedia.org/wiki/DARPA_Falcon_Project https://en.wikipedia.org/wiki/Hypersonic_speed#Classification_of_Mach_regimes https://en.wikipedia.org/wiki/Hypersonic_speed#Classificatio...